I'm trying to move a project from LabWindows/CVI 9 to Visual studio, I've been correcting errors by importing cvi libraries, now I've run into this error, but I can't find where the library comes from and it seems to be the last one I'm missing
LNK2019 unresolved external symbol _main referenced in function _WinMain#16 MES_Control_2.0.3.39 cviwmain.lib(extwmain.obj)
in the case of the other libraries it gave the same error but now I can't find extwmain.c or extwmain.lib
Your project already is configured to link cviwmain.lib. The error means it needs a main() function. You probably configured your project as a windows application(not a console application), so just remove that library because you don't need it. See this documentation for detail.
Related
I have C++ project in my Visual Studio. Additionally I placed directory with source files in it in order to use them like library in my main project.
Everything works fine while code browsing. I can define includes of library headers and navigate to functions.
I got problem during project build. I got a lot of linking errors which tells that system can't link to functions from library.
Error LNK2019 unresolved external symbol lv_task_create referenced in function monitor_init testLVGL C:\cpp_test\testLVGL\monitor.obj 1
Error LNK2019 unresolved external symbol lv_tick_inc referenced in function "int __cdecl tick_thread(void *)" (?tick_thread##YAHPEAX#Z) testLVGL C:\cpp_test\testLVGL\testLVGL.obj 1
Error LNK2019 unresolved external symbol lv_task_handler referenced in function SDL_main testLVGL C:\cpp_test\testLVGL\testLVGL.obj 1
Looks like Visual C++ is even not trying to build library.
How to tell Visual C++ to include all library files located in subdirectory in order to build and link to project?
Visual Studio does not include all the files in a directory on its own. You need to explicitly include them (you dont have to do this if you add a file within the Solution Explorer or within Visual Studio). Else it wont be listed to the compiler.
To include them, go to the solution explorer and select "Show all files". This will show you all the files in the directory. Then you can see the unlisted files marked with a red icon. Right click it and hit "Include in project" and the red icon will disappear. After this, the file will be listed as one of the project's file.
I am trying to use a library compiled with mingw in visual studio. However, I get the following linker errors:
error LNK2001: unresolved external symbol __imp___iob
error LNK2019: unresolved external symbol __imp___pctype referenced in function
error LNK2019: unresolved external symbol __imp____mb_cur_max referenced in function
error LNK2001: unresolved external symbol _fprintf
I was able to fix the _fprintf error by linking against legacy_stdio_definitions.lib as per this post : unresolved external symbol __imp__fprintf and __imp____iob_func, SDL2.
However, I have no idea how to fix the other three unresolved externals. How can I fix this? The libraries work perfectly under Visual Studio 2013.
Edit:
Okay here is an update. I moved libmsvcrt.a from the mingw lib folder into Visual Studio, and I added that to the linker settings. Now it seems to work correctly.
The libraries were compiled against an old version of the CRT. The unresolved symbols you get are internal symbols of the CRT that are present in the compiled library. You have to recompile the library against the VS2015 CRT (the Universal CRT). But I'm not sure if MinGW supports this.
If you can't do that, you have to continue to use the VS2013 compiler. (You can use the VS2015 IDE, by setting the toolset to vs2013 in the project options. But you'll still be limited to the C++ features the 2013 compiler supports.)
I encountered the same problem (library compiled with static CRT instead of CRT in DLL) and I managed to make it work by changing the two following parameters in Project Properties:
Linker > Input > Ignore specific default libraries: libc.lib
C/C++ > Code Generation > Runtime Library: Multi-threaded Debug (/MTd)
If that's not enough, there's more at following page: https://social.msdn.microsoft.com/Forums/en-US/841e5723-bce4-4340-b7b3-027dcdf90f00/
I downloaded kinect sdk both 1.8, and 2.0. I then created a new project, and edited its properties via C/C++ and included x86 headers folders
I also edited its Linker and added its corresponding x86 libraries folder.
Yet I still get linking errors, and it's not clear to me what it may be.
error LNK2019: unresolved external symbol __imp__NuiInitialize#4 referenced in function _wmain
error LNK1120: 1 unresolved externals
Any idea? Not sure what else I can do in the linker settings.
Problem resolved,
In addition to
C/C++ include
Linker library
You also need to edit
Linker Input
In here you add Kinect10.lib (or Kinect20.lib, depending on what version you're using)
I'm in the process of porting one of my project to an existing framework I've been developing. As a result I have two project, one that's the original I developed and then the ported one.
The problem I'm having is that the new project doesn't link. The error is "... unresolved external symbol ..." where the symbols should be defined in a library that's linked together with the project. By using VS command line tool dumpbin.exe I confirmed that the symbols said to be missing are in the library. The original project works fine, only by removing the library from the Linker->Input->Additional Dependencies do I get the same errors for that project.
Are there other reasons for "... unresolved external symbol ..." or am I simply not linking the library?
Details
The library in question is OpenCL.lib and the errors are "error LNK2019: unresolved external symbol _clBuildProgram#24 referenced in function ..." for all OpenCL API calls. Using the technique described in Tools for inspecting .lib files? I get the symbols for each function as one would expect.
Okay, figured it out. The library I'm linking with is only for x64 architectures, switching to that platform got it working.
Would've liked a more descriptive error from VS but what can you do...
So I am trying to compile legacy app from 32 bit to 64 bit..
I re-compiled all of the libs it used and made it look into WIN SDK6.0A x64 bit for libs..
I am using:
Visual Studio Professional Edition 2008
Visual C++
dotNet Framework 3.5 SP1
Windows Server 2008R2
Windows SDK is 6.0A
Everythings finally coming up but I am getting these weird undefined symbol errors:
error LNK2019: unresolved external symbol InterlockedDecrement referenced in function ...
error LNK2019: unresolved external symbol InterlockedIncrement referenced in function ...
error LNK2019: unresolved external symbol GetModuleBaseName referenced in ...
error LNK2019: unresolved external symbol EnumProcessModules referenced in ...
error LNK2019: unresolved external symbol EnumProcesses referenced in ...
error LNK2019: unresolved external symbol GetProcessMemoryInfo referenced
The problem is these are all win stuff from SDK.
InterlockedDec and InterlockedInc are coming from kernel32.lib
GetModuleBaseName, EnumProcessModules, EnumProcesses,GetProcessMemoryInfo are in psapi.h but also kernel32.lib or psapi.lib
I checked C:\Program Files\Microsoft SDKs\Windows\v6.0A\Lib\x64 and both libs
kernel32.lib and psapi.lib are there.
It definitely looks up the libs at right spot. I turned on /VERBOSE:LIB
and it points to the correct folder.
So I am really confused why isnt it finding them.
Any ideas???
Thanks
So I finally figured it out, kinda...
It wasnt finding psapi.lib
In Project->Linker->Additional dependencies instead of just saying psapi.lib
I gave full path to it and it worked...
not really sure why it failed to find it before but oh well...
This is very long shot (and I don't really believe this is it) but maybe the headers are not properly guarded with extern "C" for c++ compilation? Are you including system headers or just declaring the functions yourself?
Can you post your compile and link command lines, and any #def's in your code?
Does this happen if you make a simple project from scratch that only calls one of those methods?
For the record: Same problem, different solution;
I had an entry for the directory
psapi
added in the list of
Linker/General/Additional Library Directory
This resulted in the usage of the old VS2005 platform sdk psapi.lib (it only had x86, no x64 version).
After removing the entry the correct lib from the installed WinSDK x64/psapi.lib is used now.
So keep an eye out for mixings/ordering of old & new SDKs!
Obviously the full path will also work but might be a problem when you use the project on multiple machines.
In my case(migrate from VS2008 to VS2012), issue solved after adding psapi.lib in Linker->input->Additional Dependencies in VS 2012.