I get this error when I run my sln with Visual studio 2005version 8.0.50727.42 ,.NET framework version 2.0.50727 .
error LNK2001: unresolved external symbol
but I don't get the error while running the same sln through Visual Studio 2005 with .NET framework of little higher version.
I reinstalled the previous version mentioned above.but still having the same linking errors.
Requirement is to build the code with the first version mentioned above.
Please suggest way ot.
Note: the project properties are set the same while building the code with two different version mentioned above.
Try setting the /VERBOSE flag for your linker (Note: Make sure that you set it for the linker). Then look through all included libraries and verify that the one that contains the symbol in question is linked properly.
EDIT: Also note that you will not get a proper warning when linking (or rather failing to link) against 64-bit libraries in a 32-bit project.
Related
I have an MFC C++ project, which builds and runs just fine with Visual Studio 2022 on Windows 10. The project doesn't use Qt at all. After I installed Qt 6.2.1 with vcpkg, project stopped building with this linker error:
1>Qt6EntryPoint.lib(qtentrypoint_win.cpp.obj) : error LNK2019: unresolved external symbol main referenced in function WinMain
Again, there is no usage of Qt6 in my project. Going to project's Configuration Properties and disabling Use Vcpkg makes it build again. What is going on here and how to fix it without disabling vcpkg?
I created a new C++ MFC App with VS project wizard and default settings. It builds fine with vcpkg enabled.
The only reasonable explanation I can offer is that many generations ago, older VS, older Windows, my project was using a few classes from Qt4 core for a while, which caused problems, so that functionality was removed. I continued to develop it on Windows without Qt installed. Is it possible that some reference to Qt is still lurking around? How to find it? I checked settings several times and couldn't find any.
I looked at the order of library search (/VERBOSE:Lib) and with vcpkg -> Use Autolink enabled, vcpkg folders are searched first. Is there a way to make the linker search system folders first?
Here is what's happening:
1> Searching C:\src\vcpkg\installed\\x64-windows\lib\Qt6EntryPoint.lib:
1> Found WinMain
1> Referenced in msvcrt.lib(exe_winmain.obj)
1> Loaded Qt6EntryPoint.lib(qtentrypoint_win.cpp.obj)
Excluding Qt6EntryPoint.lib with /NODEFAULTLIB:"Qt6EntryPoint.lib" has no effect. Is there another way to exclude it?
This means you should open up an issue in vcpkg.
Qt6EntryPoint.lib needs to be moved into the /manual-link subfolder.
(I really hate the lazy MSBuild autolink/link everything feature of vcpkg.)
We're facing a strange issue and I've run out of troubleshooting ideas. The issue is that on some machines, which are running Visual Studio 2017 Community, we get reports that our project (which is CMake based) gets linker errors like this:
17>------ Build started: Project: ndt, Configuration: RelWithDebInfo x64 ------
17> Creating Library E:/NDT_3_0/19_Sept18/qualnet/RelWithDebInfo/exata_so.lib and object E:/NDT_3_0/19_Sept18/qualnet/RelWithDebInfo/exata_so.exp
17>ndt-main-windows-x64-vc14.obj : error LNK2019: unresolved external symbol edKJPOs664VT referenced in function "void __cdecl CheckLibraryLicenses(struct NodeInput*,...)
17>ndt-main-windows-x64-vc14.obj : error LNK2019: unresolved external symbol zzPIPSGJWa referenced in function main
...
17>E:\NDT_3_0\19_sep18\qualnet\bin\exata_so.exe : fatal error LNK1120: 17 unresolved externals
(Apologies if there are typos: for some reason they sent us a screenshot of the text instead of just a copy-and-paste of the text, so I'm transcribing. However, the parts I'm leaving out contain no mention of errors trying to open lmgr.lib which defines these symbols.)
The strange thing is, we can't reproduce these errors here when we do a fresh clone of the same Bitbucket repository they're using and follow the same build instructions. About the only difference I can tell is that our machines are running Visual Studio 2017 Professional. (Though I'm certainly not sure if this is actually the cause of the behavior differences.)
So far, what we've checked:
The library that contains the unresolved external symbols passes sha1sum checks so their Git client isn't corrupting the library binary file lmgr.lib - and same for the ndt-main-windows-x64-vc14.obj file.
The generated ndt.vcxproj project contains (the correct path to) lmgr.lib in the "Linker -> Input -> Additional Dependencies" property, as expected.
The lmgr.lib file does define the mentioned symbols (verified by Cygwin binutils nm).
On their machines, they get essentially the same linker errors whether using the Visual Studio 15 2017 Win64 generator and building from the IDE, or using the NMake Makefiles generator and building from a command prompt. Both configurations work fine on our machines.
I was wondering if somebody out there might have any ideas on why some machines might be failing to find the symbols in lmgr.lib whereas our machines have no problems completing the link stage.
(Possibly relevant: lmgr.lib contains the FlexNet Publisher licensing libraries where the symbols in both lmgr.lib and ndt-main-windows-x64-vc14.obj have been obfuscated by Flexera's lmstrip tool.)
It turned out that when we asked them to upgrade their Visual Studio 2017 Community installation to the latest service pack release, then after that the linker errors disappeared.
I have a autotools project that I've added a Visual Studio solution and project file for, and everything builds fine until I get to the linking stage. I get this output. An excerpt:
error LNK2005: "public: static bool const std::numeric_limits<unsigned short>::is_signed" already defined in abstract_syntax_graph.obj
Basically, a bunch of multiple definitions for C++ standard library stuff. I'm guessing there is something wrong with my project configuration in Visual Studio but I have no idea what would control whatever feature that is.
I faced similar errors when compiling a project under VS2015 using the /Za flag. Note that this worked fine under VS2013, but wouldn't build until I removed /Za from the VS2015 project.
This doesn't seem like an actual answer to me, I would have thought that there should be no issue disabling language extensions.
I uploaded my (VS2013) project folder and provided it to the other members of my team, but when they tried to build/run it, using Visual Studio 2012 they got this error, it also happened on their version of Visual Studio 2013.
The program can't start because MSVCR100D.dll is missing from your computer. Try reinstalling the
program to fix this problem.
They reinstalled VS2010 but no go.
I also tried to statically link my project by using /MT in the Code Generation options but now I get:
Unresolved External Symbol __free_dbg libcmptd.lib cout.obj
....25 more...
How can I get it so my project can be build/ran on my team members pc? How do I resolve the unresolved externals? It seems to happen purely with regular Microsoft files.
You are mixing C++ libraries built with different versions of the compiler (and as we know some of them are linked against debug dynamic version of VC10 runtime library). This is not supported, as different compiler versions have different ABIs.
To fix the mess you need to find libraries built with parameters that match parameters of your project. They should be built:
with the same compiler version (ex. VS 2013)
with the same configuration (Debug/Release)
against the same platform (x86/x64/ARM)
against the same runtime library variant (static/dynamic + debug/release)
You could either try to find prebuilt versions on the web or to build libraries yourself from source codes. Often, you will want to have multiple configuration/platforms for your project and, thus, you will need multiple versions of your libraries.
If your search will not succeed (for example if there is no VS2013 build for a closed source library) you could roll back your project to another version of compiler and to start over.
Any attempts to link incompatible libraries even if somehow succeeded will lead to random crashes.
This message generally states that the dll is referred to directly or indirectly in your application and is missing.
The 'D' at the end show us this is the Debug version of the file, this is DLL file is provided with the Visual Studio 2010 installation. So the MSVCR100D.dll would be provided with the installation of Visual Studio 2010.
Of course, you could be missing other versions 2008 (MSVCR90D) 2010 (MSVCR100D) 2012 (MSVCR110D) or the 2013 (MSVCR120D), each dll is provided according to the Visual Studio version.
There are a few ways to solve this:
Check to be sure that you're compiling all the components of your
project in Release mode. If this does not solve the issue continue
to the next steps.
You could solve this locally by installing Visual Studio 2010 on your
machine. This is not what I would recommend, but it would surely
overcome the issue
You could also download the file from this third party website and
copy it to your projects bin:
http://www.dll-files.com/dllindex/dll-files.shtml?msvcr100d
This option is the LEAST recommended option.
Run dependency Walker and see what file depends on the MSVCR100D.dll
and the try and fix that file in order to break your dependency. You can download depends here: http://www.dependencywalker.com/
Check to be sure that you're project is linking the correct version of
the CRT and any other libraries you may be using (e.g., MFC, ATL,
etc.)
Note: Installing the redistributables alone will NOT solve this problem, since the redistributables only contain the release version of the file MSVCR100.dll (notice no 'D')
Would it be possible that in your project you are somehow using some component/library built with Visual Studio 2010, which requires the MSVCR100D DLL?
I've created an OpenGL (GLEW) project in VS2012 and it is working perfectly. Now I've moved the project to VS2013. I've created a new project and set the project's environment the same as I did in VS2012:
Character Set:--------------Use Multi-Byte Character Set
Include Directories:--------C:\Foo\glew-1.9.0\include
Library Directories:--------C:\Foo\glew-1.9.0\lib
Additional Dependences:-opengl32.lib; glu32.lib; glew32.lib
Runtime Libary:-------------Multi-Threaded Debug (/MTd)
All code is exactly the same as before, but when I run the program, I get this error:
Error 1 error LNK2019: unresolved external symbol _main referenced in
function ___tmainCRTStartup c:\FooBar\...\Projects\OpenGL\OpenGL\LIBCMTD.lib(crt0.obj)
OpenGL
I can't see why this same project with the same settings and code doesn't work when it is an exact duplicate.
Hi #SpicyWeenie LIBCMTD is the debug version of the static multi-threaded C runtime library, and according to Microsofts licensing you cannot use than in the release version of code, I would check you are compiling in debug mode:
in debug mode use /MTd as the runtime library
in release mode use /MT as the runtime library
This will hopefully help, if not, then clean your project before building, and if that does not help either, apply liberally with swearing before creating a new project and ensuring it is a Windows Console Application and not a Windows Application (the last one has been the most common cause of the exact error you are describing for me, and happens mostly to me when moving between versions of Visual Studio (2008 to 2010 or 2010 to 2012)
Sincerely hope this helps, but if it doesnt let me know and maybe I can figure out whats wrong:)