It's pretty easy to use a library in VC++ 2008 if you create a project for it and build it alongside the other projects in your solution, but what if the library has too complex of a build process and must be compiled separately via makefile?
My library is like that, and while I've had no problem compiling it on the command line, I have no clue what to do with the resulting header files and .lib file. I've put them all in one directory and added its path to my main project's Additional Include Directories, so it finds the header files just fine. I've also added the relevant info to Additional Library Directories and Additional Dependencies.
Perhaps there's another setting I'm forgetting to set besides these three? I'd appreciate all the help I can get. Thanks.
EDIT Here are the syntax errors I'm getting:
http://pastebin.com/m72ece684
Okay, based on those errors, it has nothing to do with finding your .lib files, it's choking on the header files.
Edit:
It looks like somewhere in windows.h, there is a macro definition for X942_DH_PARAMETERS which is breaking your dl_group.h.
Instead of putting your botan headers at top, but windows.h at top, and then right before you #include the botan headers add this line:
#undef X942_DH_PARAMETERS
Or as I just discovered, that macro is defined in wincrypt.h, and if you add NOCRYPT to your preprocessor definitions it won't include that file. Since you're using a third party crypto library you probably don't need wincrypt.
While I can't exactly say what your problem is I can offer some advice as to how to find a solution. I suggest creating a simple library that contains a single method and a single class, build it, and then try to successfully link it to your project. Once you get that done on a smaller scale, try repeating the steps with your original library.
For msvc compiler you can add
#pragma comment(lib, "MYLIBNAME.lib")
in your header. This will automatically make the linker look for "MYLIBNAME.lib" in the "Additional Library Directories".
If no longer an error occures
Can't find header ...
Can't find MYLIBNAME.lib
the problem is probably related to some other stuff like wrong C runtime, debug release mismatch, ...
P.S.: If the lib is in the solution tree just setting the dependency on the lib, will cause VS to add the targetpath to the libfolder and the libname to the libraries.
Related
I know many have asked this question, but following the things suggested hasn't seemed to work for me. So I thought I'd ask for help, as I'm obviously missing something.
I've spent the past couple days writing some code that uses the boost library that allows me to open text files, translate the text into a usable data format, and save the data as a text file when I'm done with it. I built it specifically to be extendable to deal with different datatypes (specifically any object or class I make down the line) so that I could link to it as a library in my project as I do other libraries.
However, even after compiling it into a lib and adding the directory of the lib to the "Additional Include Directories", I get an unresolved external error whenever I try to include one of the header files in the library. I've also tried putting the direct path to it under Additional Dependencies (as well as just the library name with the path to the directory set in Additional Include Directories and Additional Library Directories. I also tried it with only one of those on at a time and it still failed).
Is there something I'm missing? How can I compile this code I'd like to reuse and link to it in new projects without copying the cpp and h files into my solution every time? Would a DLL work better/easier? If so, how would I go about compiling it as a dll and linking to it?
Thanks for reading this wall of text. Any help you could provide would be great.
Ok. While it's not the exact solution I was going for, I managed to figure this out. For anyone running into this problem, there's a wonderful tutorial that explains how to make DLL files and make use of them (at least on windows, don't have any computers using an alternate OS set up yet to test the DLL on). You can find it here.
http://programmingexamples.wikidot.com/blog:1
The gist of the problem is you need to also keep a copy of the .h file handy to include in your project. (what I did is created a directory on my C drive that holds the libraries I'm making, and in that I have a folder for the .lib files and a folder for the .h files.) Either import the .h file directly into your project directory or add it to your project properties (C++ -> General -> Additional Include Directories ). Make sure for that, you're linking to the directory, not the file itself. In the linker, you need to add your .lib file to the Additional Dependencies section (Linker -> Input -> Additional Dependencies). You can put the whole path here, or you can just put the file name, then tell the program where to find the directory it's in (add the path to the directory to Linker -> General -> Additional Library Directories)
Hope this helps anyone else who managed to miss something that everyone else seems to understand instinctually :P
I ran into a strange problem with a Visual Studio 2008 project I was working with recently.
I am trying to compile a new static library that uses functions from another static library. (Let's say Lib1 is my static library project, and Lib2 is the lib file that Lib1 depends on).
I am able to build lib1 without issue; It includes the header files for lib2 and calls its functions, and there are no problems.
The problem is when I build a separate test project that has Lib1 as a dependency; it won't build and I get linker errors. The unresolved externals are the functions I am trying to call within Lib1 that are from Lib2.
This is all fixed when I include Lib2 in my test project as well.
This all makes sense to me of course; I can test that Lib2 is not being built into Lib1..
My question is: is there a way to do this? I would ideally like to be able to deploy Lib1 as a standalone lib without requiring Lib2. (Lib2 is actually just a Lib from the Windows Platform SDK, so it's not really a big deal...)
Is this not allowed because it would allow people to "hide" third party libraries in their own, or something?
What would be a professional approach to this problem?
Thanks!
--R
I would not advise using a librarian to take Windows' library contents into your own library -- it's likely that that's against the license.
I see two possibilities
Documenting the dependency
Using a #pragma in your .h file that requests the .lib to be linked against. If VS can find it, it's the same as including it on your link line.
http://msdn.microsoft.com/en-us/library/7f0aews7(VS.80).aspx
#pragma comment(lib, "libname.lib")
You need to use a tool called a librarian to do this. A librarian allows you to create and modify library (.lib) files. In visual studio check under the Librarian section of your project properties. A command line version also comes with visual studio (lib.exe).
Just document the dependencies of your lib.
As long as the library you depend on is available to anyone that could use your library, this is the preferred solution. Especially considering that the library user could also depend on this platform SDK lib - if you had it embedded then he'd get funny linker errors with multiply defined symbols.
This is a fairly normal problem - you wouldn't normally attempt to include 'lib2' into 'lib1' but simply document that it's required to be linked against in order to work. There is nothing wrong with declaring the use of other libraries (apart from any licensing issues of course) so you are already doing the right thing.
If you really want to do this, you can extract the .obj files from Lib2 and add them to Lib1.
See How to Extract .OBJ Routines from .LIB Files Using LIB.EXE -- I hope it is still relevant for VS2008.
Instead of simply documenting your dependencies, use #pragma comment(lib, 'lib2name') in your code to make the linker pull in the other library automatically. Since you said you're using a standard library that comes with the SDK, this should eliminate all burden on the application.
We have a large project using VS2008 and boost 1_42. I'm trying to upgrade to VS2010 and boost 1_44. I installed VS2010 and boost 1_44 and converted the project. Now I am trying to build, and everything compiles, but fails when linking:
LINK : fatal error LNK1104: cannot open file 'libboost_thread-vc90-mt-1_42.lib'
I have changed the include and lib directories to point to the new boost 1_44 files and I have renamed the old boost 1_42 directory.
Why is the linker still looking for a vc90-1_42 file, when it is only using 1_44 headers? Is there a way that I can determine WHY the linker wants this file? The linker obviously thinks it needs the file, but why?
I have cleaned the project and I am re-building to ensure any old build files are erased.
I've run into exactly this problem a couple of times too. It's usually been some old temporary files but like in your case cleaning didn't always do the trick straight away. Does your project include any static libs that might have been built with 1.42?
Something you can try which may or may not be helpful in tracking down your issue:
Rename the old boost directory back to it's original name
Clean the solution
Under C/C++->Command Line->Additional Options add "/showIncludes"
Under Linker->Command Line->Additional Options add "/verbose:lib"
Rebuild all
Then when you build you'll be able to see at which point 1.42 headers are included, etc. in the output window. Somehow doing this helped me in tracking down where the problem was.
Along with changing the lib directory, you need to change the name of the boost library. That's in the Linker | Input section of the project settings.
Your added comment makes it clear that the dependency on the Boost 1.42 library was being created indirectly by another library that hadn't been rebuilt.
For this you basically have two choices: either add that library as a project to your main solution, and make sure it has enough dependency information that it'll be re-built when you upgrade Boost, or use the /Zl compiler switch when you build your library. This tells the compiler you're building a library so you do not want to embed library dependencies like this.
Boost uses
#pragma comment(lib)
command to inform the linker of libraries it needs to link with. It is not an error. If Boost says you need it, it's likely you do.
On How can I find out why the linker wants this file?
There are programs which will go through your app and dlls/libs and report the content of manifests and what the binaries report they depend on. You could then scan the report for the unexpected libraries being included. We used this mainly to find libs including the previous version of the VC runtime.
Have not used the one we had in about 5 years though, now if only I could remember the name of the app!
DependancyWalker (depends.exe) will allow you to see dependancies of dll/exe but not static libs.
You could open each binary as a 'file' in MSVS and look at the manifest content by hand, but I imaging this would be a bit painful. I've not tried this with a static lib.
How do I properly include libraries in C++? I'm used to doing the standard libraries in C++ and my own .h files.
I'm trying to include wxWidgets or GTK+ in code::blocks and/or netbeans C/C++ plugin. I've included ALL libraries but I constantly get errors such as file not found when it is explicitly in the include!
One error: test1.cpp:1:24: wx/msw/wx.rc: No such file or directory : Yes the .h file library is included; what am I missing?
Do I need to be importing other things as well? Is there a tutorial for this? Obviously my shoddy textbook hasn't prepared me for this.
Firstly, header files are not the same thing as libraries. A header is a C++ text file containing declarations of things, while a library is a container for compiled, binary code.
When you #include a header file, the compiler/IDE needs to know where to find it. There is typically an IDE setting which tells the compiler where to look, or you can do it from the command line, normally using the -I switch. It sounds to me as if you have not set up the path to search for header files on in your IDE.
This means that test.cpp included "wx/msw/wx.rc" but that file cannot be found by your compiler. How to fix this depends on your compiler, but you need to find where wxwidgets is installed and add that to your "Include Paths" so that your compiler knows where to search for it. You can also put a more complete path to it in the include directive.
If the files are present in the same directory as test1.cpp, then probably you use the wrong kind of include. #include <...> is usually used for code that resides outside of the directory that your project is in. #include "..." is for includes inside your project directory (and then if they aren't found there, search in the same places as #include <> would).
It is quite an old question and this didn't really answer it for me.
I reinstalled wxwidgets into the root directory as someone suggested that being in a directory with a space in the name may be part of the problem.
Then I went into project > build options > search directories and removed all entries pointing to original install.
And this fixed the problem
I am trying to link some Boost .hpp files with Monodevelop, but I don't know how to tell the IDE where Libraries are.
If I want to include the array.hpp file, I write #include<directories/array.hpp>, but because this file makes calls to other files, and the directories to those files in the array.hpp file are only /boost/somefile, there are several path errors. What can I do? Thanks in advance.
For libraries like Boost you'll need to add the path to the includes/libraries in your project configuration.
In MonoDevelop this can be done by choosing Project->Options->Configurations, then choose the appropriate build type (you'll probably want to edit both Debug and Release eventually), and then Code Generation->Paths.
The Library section is for your built libraries, if any, and the Include section is for stuff like headers and includes.
In this particular case you'll want to add /usr/local/boost to the Include section (change the path as necessary).
Once you've done that, you should be able to use Boost like so:
#include <boost/array.hpp> // make sure you use angle brackets