I frequently have this problem when I try a new library. This time I work with PointGrey Camera and try to use its API libraries (some dll, lib, header files). Mostly, problems were fixed by configuring the SDK (I'm using VS2008) Tools/Options/VC++ Directories/include files(/library files)(/executable files),
I also tried with project configuration:
+ project properties/linker/input/additional dependencies
+ project properties/linker/General/Additional Library Directories
This time, with all this, I still have the error.
Is there a general method to deal with this problem?
do I need to understand this diagnosis from VS2008?
Error 1 error LNK2019: unresolved external symbol __imp__flycaptureGetPacketInfo referenced in function "enum FlyCaptureError __cdecl initializeStandardEventSizes(void *,struct FlyCaptureImageEvent * const)" (?initializeStandardEventSizes##YA?AW4FlyCaptureError##PAXQAUFlyCaptureImageEvent###Z) main_2.obj test
does using analysis tool such as Dependencies Walker ensure to solve these problems well??
This message says that you used a symbol (a function or a variable) in your code. This symbol was probably declared somewhere (most likely in a header file you included in your code) otherwise there would have been a compilation error. When the linker searched for the symbol (in both your object files and the lib files you instructed it to look in) it couldn't find it.
That usually happens because you forgot to let the linker know about a lib you want it to search in.
Most libraries come with a set of instruction that is supposed to help you set up everything correctly and avoid running into these problems.
This problem has been solved lately. I installed the incompatible library of PointGrey. That's why it didn't work. But this says something between "incompatible library" and "unresolved exertal symbol error"
Related
I have the following linker error in one project of a Visual Studio 2013 solution:
error LNK2019: unresolved external symbol "__declspec(dllimport) public: static class std::locale::_Locimp * __cdecl std::locale::_Getgloballocale(void)" (__imp_?_Getgloballocale#locale#std##SAPEAV_Locimp#12#XZ) referenced in function "class std::ctype<char> const & __cdecl std::use_facet<class std::ctype<char> >(class std::locale const &)" (??$use_facet#V?$ctype#D#std###std##YAAEBV?$ctype#D#0#AEBVlocale#0##Z)
In all projects I linked the run-time library dynamically (/MD).
I considered the hints in the following posts:
C++ linker unresolved external symbols
What libraries do I
need to link my mixed-mode application to?
Boost -
Unresolved external symbols when compiling linking with /MT instead
of /MD
Link error 2001:unresolved external symbol
Linker errors between multiple projects in Visual C++
but was not able to solve this issue.
Actually, I am not even aware of where in the project _Getgloballocale is used. Maybe it would also help to know the lib in which _Getgloballocale is located.
The projects use the following libraries:
cURL
Protobuf
libboost_thread-vc120-mt-1_56.lib
libboost_system-vc120-mt-1_56.lib
libboost_python-vc120-mt-1_56.lib
libboost_filesystem-vc120-mt-1_56.lib
In all projects I linked the run-time library dynamically (/MD).
As others noted, verifying this might be less obvious than appears. For one, some of your libraries might drag in external dependencies that do rely on a mis-matching runtime.
Suggest you link with /VERBOSE on (in your EXE project, properties / linker / general / show progress), and search the output dump for MSVCR. You might catch a different version (msvcr100.lib) or a different configuration (msvcr120d.lib). Also try to search for LIBCMT - that is the library for static linking of the runtime. These typically appear as part of a /DEFAULTLIB linker directive, and you should be able to understand from the dump in which library context this directive is present.
You can also post here the verbose output (or the relevant snippets), and we can try to help interpret it.
Help me guys,
I've been searching for a really long time.
I'm using visual studio 2010 and I tried to include an external lib but I get an unresolved external error.
The external project is composed of files in the following way
backend.cpp
//some functions
frontend.cpp
//some functions
header.h
I build this project using SCons then I includes the .lib file in the project and refered to its path and I copied the .h file to msvc directory .
VS seems to access and read the functions in backend.cpp(from the auto complete) but when I run the project it says that there is an unresolved external # the called function
I'm not a Visual Studio expert, but I guess that it being able to auto complete your code is associated with it finding the headers of your source code.
Unresolved external means that the compiler can't find the object files in the linking process. This could mean that you failed to add the lib files correctly, or that you are missing some .cpp file.
That may happen for a variety of reasons. But all of them end up being one of the following:
You are not linking the correct .lib file.
The symbol name you are using in your program is not identical to the one provided in the .lib.
The first one is easy enough to check, so please, double check it.
The second one is trickier. The symbol name used in your program is output in the error message "unresolved external symbol abc", or whatever. The symbols available in the library can be listed with the command: dumpbin /all name.lib.
If you cannot find the problem, please post the exact error you are getting and the output of the dumpbin program.
I am trying to build an xll addin for Excel using appropriate framwork downloaded from MS website. I am getting the following linker errors:
1>FRAMEWRK.obj : error LNK2001: unresolved external symbol _Excel4
1>FRAMEWRK.obj : error LNK2001: unresolved external symbol _Excel4v#16
I think that these should be defined in XLCALL32.LIB included in the package from MS, but I don't know how to check it. Moreover, added the folder containing this library to the Additional Library Directories, without luck.
Hence my questions:
(1) How can I check what is in XLCALL32.LIB?
(2) How can I see which files the linker is using to see if my library is actually included?
In your project properties, Under Configuration Properties->Linker->Input, you will see 'Additional Dependencies' - these are the files the linker is using. Assuming that _Excel4 and _Excel4v are defined in XLCALL32.LIB (which I think they are), you simply need to ensure that this file is specified in this list.
Does anybody know about this linker error in Visual C++?
PGPkeys.obj : error LNK2001:
unresolved external symbol
_imp_PGPclCloseClientPrefs
Unresolved externals are usually due to missing binary (a DLL or a static lib). Check directory paths to libraries your code needs.
You need to find out in what library/DLL the symbol PGPclCloseClientPrefs is defined.
If mbadawi23's answer doesn't solve your problem, think about the following:
I think imp might indicate an environment mismatch, so make sure you're using the linker that came with VC++ 6. I do not remember VC++6 mangling imported/exported symbol names in that way, but, I could be wrong.
If worst comes to worst, look up making a def file for the DLL in which PGPclCloseClientPrefs lives and export the symbol that way.
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
What is an undefined reference/unresolved external symbol error and how do I fix it?
I am working on wrapping a large number of .h and .lib files from native C++ to Managed C++ for eventual use as a referenced .dll in C#.
I have the .lib files linked in and everything has been going smoothly so far. Upon wrapping the latest .h file, I hit a snag when 2 functions came back with the link error:
error LNK2019: unresolved external symbol __imp__htonl#4 referenced in function
"public: void __thiscall Field::setCharacter(unsigned char,int)"
(?setCharacter#Field##QAEXEH#Z) myutils.lib
I have referenced myutils.lib in the linker options, so that shouldn't be the issue.
What's strange is that I have about 20 functions in this particular .h file and all of the rest are linking just fine except for 3 functions.
Any ideas?
The missing symbol is __imp__htonl#4, which is a C++ mangled name for htonl, which is a function that converts a long value from host to network order. The #4 is used to mangle the input parameters and is part of C++ support for overloaded functions to allow the linker to resolve the right function w/o name collisions.
Make sure that you are linked to the network library that you are referencing this symbol from. Presumably your package is using some special definition of this symbol, instead of the MACRO that it usually is.
Are you sure the signatures match? Be sure to checked for signed-ness and const-ness. Also, make sure functions aren't inlined.
I ran into this error when I compiled against a library and then changed the library before linking. Make sure your headers are the same ones provided by your library (not copied from another architecture, etc). Of course, make sure you're linking against ws2_32.lib (-lws2_32 for mingw/gcc).
Additionally, if you are using GCC/mingw you may want to take a look at this: MinGW linker error: winsock