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
Related
I have been programming a game in c++ using the sfml library. However, I would like to adjust some of the code of that library, and use that altered code in my project.
So instead of linking the dll I would like to add the source code and then play with that source code. (e.g. for speed optimization).
I know that doing something like that is generally speaking a bad idea. Howeover, I want to learn by playing around a bit and trying different things.
So how would I add the sfml source code to my c++ project in MS visual studio. Note that I am a total noob. I already tried adding the sfml folder that I downloaded from git in the project properties page called "Additional Include Directories", but i am getting errors, of the form "Cannot open include file: 'SFML/Graphics/GLCheck.hpp': No such file or directory" so I guess that i have not yet done enough.
If you want to modify the source code in the library, all you'd have to do is just navigate to where you have SFML installed and go into the code files with a text editor and edit them.
Then, you could link the library to your VS project the same way you would normally but that library is now modified by you.
Seeing as you have a search directory issue already in VS, you must fix that first. Fix that and then go and modify the library's .hpp, .h, .cpp, whatever files in-place.
To fix the search issue.... I don't use VS for graphics, I use CodeBlocks so I am not sure about their GUI to link libraries and change search directories... but, find out where you installed SFML. Check your /usr/include/, it's probably there. Specify that path in the search directories. Just go and find where that GLCheck.hpp file is located. For Example: Say it's full path is /usr/include/SFML/Graphics/GLCheck.hpp... then /usr/include/SFML/Graphics/ or just /usr/include/ (VS might handle it recursively) needs to be in the list of SEARCH DIRECTORIES.
I am trying to open sdl2 in my project on Visual C++ 2012 but i keep getting this error:
error LNK1104: cannot open file 'SDL2.lib'
I added the additional libraries and include folder but no luck..
I added the link to the libraries through the linker but i get the same error..
what should i do?
I'm referencing VS 2010, but I've read before that some people have had errors when using the VC++ Directories in their project properties as opposed to the Linker->General->Additional Library Directories.
Unfortunately, there really isn't much more to do besides making sure the directories are linked properly. There really is only one answer to this question. It also may depend on the download of SDL you chose, are you donwloading the Development Library as opposed to the binary?
Watch this video https://www.youtube.com/watch?v=or1dAmUO8k0.
In summary, you want to add the path include folder here: (configuration properties> C/C++ > General> Additional Include Directories),
and add the path of the lib folder here: (configuration properties> Linker > General> Additional Library Directories)
and finally, link .lib file in: linker > input > Additional Dependencies.
It seems like you didn't add your library directory path in VC++ Directories/Library Directories.. You have to link your library directory path (Where you have save you libraries of SDL) in your program. After adding, it will definitely work
I would like to add for others experiencing this problem that its an easy mistake if you are using the Development Library to link to the lib folder. SDL needs you link to either the x86 or x64 folder in the lib folder.
If you run or compile your program before you make those required changes of SDL then you will get this error always.. so first add a c++ file then make those changes and then write something and try to run ..this time it will never give this error
It seems like VS can't find the lib files. There are two ways you can do this. One is to configure the appropriate directories in VS as TwinkleBearDev's article shows. Another is to put the libraries directly where VS would look for them, as my article shows. I don't know if the folders for VS2012 are the same though - might be slightly different.
I have been using libcurl in a C++ project.
I have added the libcurl Include and Library directory's to the VC++ Directories and added the .lib file to the Linkers Input Additional Dependencies.
Everything works fine but when I check in my code (TFS) and somebody gets it on another machine they cannot build etc due to not having libcurl installed on their machine or installed in different paths etc.
How do I add all the necessary files to my C++ Solution so that anyone getting the project from source control can build and link without error.
Thanks
The solution I went with was too add the library file to a folder within my solution, then add
$(SolutionDir)libs\curllib.lib
To the Additional Dependencies within Linker->Input
You can not add the library to the solution. you should distribute the library along the source code. Place it in a subdirectory of the project so that it goes along the whole project source. Then configure the path in Additional Library Dependencies. That way the people should be able to link appropriately when building from source.
So I was beating my head against my desk for days trying to figure out why my MFC project kept failing at link phase because it couldn't find mfc40.lib. I checked for #pragma comment, I checked for lib inputs in project settings, i grepped folder after folder, I could find NOTHING.
Just before I was about to lose my mind, I realized that grepWin ignores LIB files for some reason, so I opened up an old lib in my text editor and saw this:
-defaultlib:mfc40.lib -defaultlib:mfcs40.lib -defaultlib:msvcrt.lib -defaultlib:kernel32.lib -defaultlib:user32.lib -defaultlib:gdi32.lib -defaultlib:comdlg32.lib -defaultlib:winspool.lib -defaultlib:advapi32.lib -defaultlib:shell32.lib -defaultlib:comctl32.lib /include:_afxForceEXCLUDE /include:_afxForceUSRDLL /include:__afxForceSTDAFX -defaultlib:LIBC
-defaultlib:OLDNAMES
For some odd reason the above human-readable portion was actually in the LIB file itself, so I can only assume that because I link against this lib directly, it is INDIRECTLY forcing the inclusion of mfc40.lib (and friends).
Is this what is happening? Why is the above inside the LIB file? An explanation of why this happens would be a bonus.
Also the lib in question is from the Exchange SDK. I'm compiling this MFC project in VS2008.
If when you created the project for your library you chose an MFC based library, whichever version of MFC is available gets added as a default library. To remove it, in your project properties go to Linker > Input > Ignore Specific Libraries and enter mfc40.lib.
More info on that property: http://msdn.microsoft.com/en-us/library/3tz4da4a%28v=VS.90%29.aspx
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.