I've been having a bit of trouble using LibCurl with Visual Studio 2010. Keep in mind I'm pretty new to C++.
I built the library according to the instructions on the libcurl website and tried to point my project to the include directory, libcurl.lib, etc but when I try to build the project I get a bunch of LNK2019 errors.
Can someone please walk me through how to tell Visual Studio where the include files, .lib file, etc are (i.e. all the steps after building LibCurl up to using sample code in a test project)?
Thanks in advance.
error LNK2001: unresolved external symbol __imp__send#16
Hurray, we have an error message. Add ws2_32.lib to the Additional Dependencies setting. The MSDN Library lists the required import library at the bottom of the article for each API function.
Interpreting the linker error is important to diagnose these errors. Ignore the __imp__ prefix, that's linker glue. You can tell it is trying to find the definition of the send() function. That's a standard socket API function. The MSDN Library article for send() told me you need to add ws2_32.lib to the dependencies. The article is here, scroll to the bottom. This same information should also be available in the library documentation.
open the project settings dialog window first (right click >> properties)
this contains everything in regards to getting the project configured
find "Linker", then expand it and go to "Linker >> General"
under "Additional library directories" add the location of the ".lib" files
then go to "Linker>>input" and add the name of the library files you want to include
Related
I'm trying to create a native HoloLens 2 C++ application with OpenXR. In the Microsoft OpenXR-MixedReality example I discovered the XrSceneLib_uwp project which has the configuration type set as static library (.lib) in the Visual Studio properties. Accordingly to that I tried to add it as a library in my solution which also has a Core Application (C++/WinRT) in it where I want to use the functions from XrSceneLib_uwp. In my thinking it makes sens because I can use the library for example to create a holographic title scene without much effort. The problem here is that when I build my solution I'm getting linker errors and I don't know how to fix them. I'm also relatively new to Visual Studio (22 in my case) and most likely I'm just doing someting wrong in the linking process.
Linker error when I try to build:
Error LNK2019 unresolved external symbol xrGetInstanceProcAddr referenced in function "public: __cdecl `anonymous namespace'::ImplementXrApp::ImplementXrApp(struct engine::XrAppConfiguration)" (??0ImplementXrApp#?A0x934f03db##QEAA#UXrAppConfiguration#engine###Z) CoreApp3 \repos\CoreApp3\CoreApp3\XrSceneLib_uwp.lib(XrApp.obj) 1
My solution explorer
Here is what I do:
I copy and paste the shared and openxr_preview folders from the OpenXR-MixedReality .zip file in my project folder.
Add XrSceneLib_uwp.vcxproj in /shared/XrSceneLib as an existing project to my solution.
Add the path to the copied shared and openxr_preview folders in Properties->Configuration Properties->C/C++->General->Additional Include Directories.
Add also the path to XrSceneLib_uwp.vcxproj in Additional Include Directories in my main project (CoreApp).
Add reference in CoreApp to XrSceneLib_uwp (Add->Reference->Projects).
After that everything works fine and I can even build the solution. But when I try to use the library I'm getting these linker errors. I don't understand why it works in the OpenXR-MixedReality examples but not when I try to implement it on an different project. What am I missing? I assume that XrSceneLib may not have been designed to be used externally in other projects but at the same time I think it should be possible somehow.
I also tried to add Additional Library Directories and the missing object files but either I have done something wrong or it just simply does not work.
I really appreciate any help.
I think the linker is failing to find the OpenXR Loader. The sample projects in the microsoft/OpenXR-MixedReality github repo link to the OpenXR Loader using the NuGet package manager. I get the same linker error if I purposely remove the NuGet package references from the sample projects.
You can either link to the OpenXR Loader using NuGet or you can build the OpenXR Loader youself. Take a look at the "Using OpenXR in an existing project" section on the microsoft site:
https://learn.microsoft.com/en-us/windows/mixed-reality/develop/native/openxr-getting-started#using-openxr-in-an-existing-project
I have problems building my code that is using static lib detours. I am trying to do an old basic CTF. For that I want to get into detours.
Whenever I try to build my .dll file I get an issue
LNK2019 unresolved external symbol _DetourTransactionBegin#0 referenced in function _DllMain#12
Now, I have built the detours library using 3 different version of the visual studio dev console.
I have tried firing 'vcvars32.bat' and then using nmake to build the library which was able to build it, but I get the above error during linking my .dll. I have also tried building it with 'vcvarsamd64_x86.bat' and then using nmake to build it which also was able to build the library, but I still get the same error as above during linking.
I have tried the usual stuff: the include folder for detours.h is added to C++/General/Additional Include Directories.
Under Linker/Additional Library Directories I added them as follows: "C:\temp\det_retry\lib.X64";"C:\temp\det_retry\lib.X86";%(AdditionalLibraryDirectories).
And also under Linker/Input/Additional Dependencies I have the following: detours.lib;%(AdditionalDependencies)
What am I missing here? This is a blocker for me for a couple of days and I am reiterating the same steps trying to figure out what's missing but I cannot see. I'd really appreciate the input.
I am sure I am using the newest version because I have downloaded (cloned) detours from the ms github page.
It appears your "Additional Library Directories" are setup incorrectly or contain invalid entries rather. They look like actual library file entries (i.e. pointing to some specific files) versus being only directories (e.g. "my/lib/path/for/my_project/"). Visual Studio's naming conventions are somewhat cryptic but they should be directory entries only. There should be an entry to whatever directory contains the detours.lib file (e.g. "MyProject/Libs/MSDetour" ... where MSDetour is a folder with the "detours.lib" in it) and then Visual Studio should find the library and link everything correctly.
As a side note, if you are using the Visual Studio developer console for building your project/solution you might want to look into CMake ... it is, in my opinion, significantly easier to work with (less "settings" digging) and maintain in the long-run.
Some back story: I am trying to get the bolt-lmm software to compile on a Windows machine, because it would be a nice addition to the research group I am in. The developers of the software have only made a linux static executeable, but made the source code available. I am used to programming in R or python, and this is my first ever encounter with C++.
I have solved a fair bit of problems, but for some reason I have not been able to get visual studio to link properly with Nlopt-2.4.2.
I downloaded it
and followed the steps given there on how to install it.
I can tell I have done the same to link the Nlopt library to the project as is described in How to add additional libraries to Visual Studio project?
I still get errors like:
Error LNK2019 unresolved external symbol __imp__nlopt_create referenced in function "public: __thiscall nlopt::opt::opt(enum nlopt::algorithm,unsigned int)" (??0opt#nlopt##QAE#W4algorithm#1#I#Z) boltCompiler C:\Users\au483192\source\repos\boltCompiled\boltCompiler\NonlinearOptMulti.obj 1
(there are a total of 12 of this type of error, and an error link 1120, which just tells me there are 12 unresolved eternals.)
I hope this is enough information to provide a hint of what is going wrong.
I did some more digging, and it seems the linker needed more than just the folder for the .lib file.
This post sums it up:
Linking a static library to my project on Visual Studio 2010
Essentially you just need to tell the linker the placement of the lib and the actual name of the .lib file.
Hopefully this will help others who forgot/did not know that added library names manually could be needed for some libraries.
TL;DR:
open configuration properties for the project > linker > general
Then add the path to the .lib file in the "addition library directories" line
Then (still in configuration properties) go to linker > input
add the .lib file name to the "addition dependencies" line, e.g. libnlopt-0.lib (don't forget to separate with ";")
I've been trying to compile tulip using cmake to generate visual studio 2012 project files. It's giving me lots of trouble. I don't know how to get this to build. I've been trying to get visual studio to build this for 4 days now, and I'm extremely frustrated. Essentially, I follow the steps here, and then set the variables CMAKE_LIBRARY_PATH AND CMAKE_INCLUDE_PATH according to these instructions.
To get to where I'm at, all you have to do is download tulip, and:
Unzip it, create a separate build directory outside of this source directory
Open CMake-gui to the source and build directories
Hit configure. Check use qt5, tell it where qmake is (make sure it's qt5)
You need some dependencies as described in The Independent CMake tutorial. Grab all those dependencies
As you continue to hit configure, specify each of the directories that it asks for as it errors out. It should ask for freetype, glew, zlib and sphinx. It shouldn't ask for where libxml or libpng, or libjpeg are. I don't know why it doesn't ask for those.
Generate, and then browse to the ALL_BUILD that you've generated. Open it with visual studio
try to build it with visual studio.
In those instructions and in the process of getting CMake to generate the visual studio build files, it specifically asks for freetype's location. But in my build, it doesn't have a clue how to link the freetype library.
Here are the errors that I get
Here is my CMakeCached.txt
I know that many people aren't going to want to exactly try and go about replicating the build environment, so I've uploaded my build directory to dropbox. You can pull the entire thing down, and then open it in cmake gui and open the visual studio files in there too.
https://www.dropbox.com/sh/qsvukh9t5gb6bvt/tOfOBxWgd0
The linker errors you point to (mostly "unresolved external" errors) indicate that there are missing libraries on the link command line.
That is most likely happening because target_link_libraries calls in the tulip project are either being skipped or being called with library names that do not match the library names on disk.
Open up the solution in Visual Studio and right click the project and choose "Properties" -- look at the "Linker > Input" panel at the "Additional Dependencies" field. That should list all the libraries it wants to link to. Is there a freetype library listed there? Does that library exist in the referenced location on your disk?
There could be a mistake in the tulip project, or there could just be something wrong with your build/install of freetype...
UPDATE AFTER SOME CHAT:
Or it may be that you have some libraries built for x86 and some for x64... or maybe some for Debug and some for Release... or maybe even some with the MinGW compiler and some with the Visual Studio compiler. If that's the case, start over, from a clean slate, and build everything with a consistent compiler, configuration type and architecture. Then report back again with an update and see if the problems still remain.
I do with Dave,
You should try to fix your error 1 by 1.
The first error seems to be a link error:
Error 1 error LNK2019: unresolved external symbol gzread referenced in function "public: virtual int __cdecl gzstreambuf::underflow(void)" (?underflow#gzstreambuf##UEAAHXZ) C:\Users\kenne_000\tulip-build\tulip-build-debug\thirdparty\gzstream\gzstream.obj gzstream
gzstream is a third party lib included with tulip source in:
thirdparty\gzstream
from
thirdparty\gzstream\CMakeLists.txt
you can see that the missing symbols should be coming from ZLIB.
However your CMakeCache.txt indicate that
ZLIB_LIBRARY:FILEPATH=C:/Users/kenne_000/dependencies/zlib128-dll/lib/zdll.lib
is found.
So the question may be, was this dependency compiled with the same compiler?
Don't you have compiler-specific name mangling issue ?
I have migrated my VC6 application to VS2005, all my code got compiled with some changes and there is no compilation error.
But I am getting a linking error LNK1104.
LINK : fatal error LNK1104: cannot open file 'mfc42u.lib'
I have imported the dsw of VC6 in Visual Studio 2005, not sure from where it is still referring to the mfc42u.lib (I assume its library of VC6).
Please guide me how to get rid of this error.
This library is referred from Linker section of your project settings, specifically "Additional libraries" or something like this (do not remember the name of the setting exactly) - there are libraries needed to be linked with listed there. So just replace the mfc42u.lib with mfc8u.lib or whatever is the relevant version of mfc installed with your VS distribution there.
probably your linker settings aren't set properly. Go to Project Settings->Configuration->General->Use MFC Libraries and make sure the value is set to 'Use MFC in a shared library'. If you are able to build properly, then you can change it back to 'Static' to use the new library.