I've been tasked to upgrade an app of ours from VC++6 to VC++ 2010. After spending a bit of time on it, I've managed to get it to compile successfully. However, linking fails :(
The linker error I'm getting is:
Error 33 error LNK2019: unresolved external symbol _SQLConfigDataSource#16 referenced in function "protected: void __thiscall CReportPropertyPage4::OnViewReport(void)" (?OnViewReport#CReportPropertyPage4##IAEXXZ) <redacted>\ReportPropertyPages.obj
While I'll be the first to admit I have zero experience debugging linker errors, I've done some research online to find that I needed to include the proper .lib file for the linker.
So, I went ahead and opened the projects property page and went under linker and added a reference to the .lib under "Additional Dependencies" on the Input tab.
$(ProjectDir)\lib\odbccp32.lib (Note, I did actually make a copy of the .lib into the above folder).
But, no dice.
odbcinst.h is the file that defines the function SQLConfigDataSource (and it's included):
BOOL INSTAPI SQLConfigDataSource (HWND hwndParent,
WORD fRequest,
LPCSTR lpszDriver,
LPCSTR lpszAttributes);
And my associated call to it:
CString strParameters;
strParameters.Format(
"DSN=<Redacted> ASCII\0"
"Description=<Redacted> ASCII\0"
"CharacterSet=ASCII\0"
"ColNameHeader=False\0"
"Format=TabDelimited\0"
"DEFAULTDIR=%s\0"
"EXTENSIONS=txt\0\0", strTempDir );
if( SQLConfigDataSource( NULL, ODBC_ADD_DSN, "Microsoft Text Driver (*.txt; *.csv)",
strParameters ) )
Related
I am trying to get protocol buffer to work but linking problems occurs.
All the errors looks something along like this
error LNK2019: unresolved external symbol "public: bool __cdecl google::protobuf::MessageLite::ParseFromArray(void const *,int)" (?ParseFromArray#MessageLite#protobuf#google##QEAA_NPEBXH#Z) referenced in function "void __cdecl ReceiveRequest(bool *)" (?ReceiveRequest##YAXPEA_N#Z)
I am using visual studio pro 2013 and this is what I have done:
I compiled the protocol buffer and added the libprotobuf.lib to the project(Add->Existing Item->libprotobuf.lib)
I've added the header files in C/C++ -> General -> "Additional Include Directories"
I have tried to add the library all the different ways I know but I still get these linking errors...
Any idea what I might have done wrong?
// Eric
You need to include the generated protocol buffer .cc (and maybe the .h) file (ie the file with the specific getters and setters for your specific proto) in your VS project (ie there has to be a little icon for them in the solution explorer) or else visual studio won't generate the code for it and thus there's nothing to link to.
Make sure you have the correct libraries for your architecture (e.g. x86 / x64).
That has caught me out a few times.
I'm new to MFC.
I'm trying to make a DLL in MFC, which links to another DLL.
The problem is when I try and compile, I get a LNK2019 error thrown at me for a function present in the DLL which I'm trying to link.
LNK2019 is when the DLL or the function inside the DLL is not being found.
I've taken all steps, the DLL is placed in a known location, the lib is placed in a known location too, it's been added in the additional dependencies, all correct switches have been applied ( ones I know of anyway ).
I've used Dependency walker and I know the DLL, to which I'm trying to link, exposes this function.
I've other examples of use of the function, and I'm trying to use it exactly like it.
The .lib and .dll are in agreement, i.e., they're consistent with each other.
But still the error persists.
EDIT
This is the error message :
Error 2 error LNK2019: unresolved external symbol
"__declspec(dllimport) public: bool __thiscall
PwServer::Connect(wchar_t const *,unsigned long,unsigned long *)"
(_imp?Connect#PwServer##QAE_NPB_WKPAK#Z) referenced in function
"public: bool __thiscall CPwServer::Connect(class
ATL::CStringT > >,unsigned long,unsigned long *)"
(?Connect#CPwServer##QAE_NV?$CStringT#_WV?$StrTraitMFC_DLL#_WV?$ChTraitsCRT#_W#ATL#####ATL##KPAK#Z)
And this is the call I use to access the DLL.
bool conn = PwSrv->Connect(_T(""));
Dumpbin Export of the function :
25BE6 ?Connect#PwServer##QAE_NPBGKPAK#Z 25BE6 __imp_?Connect#PwServer##QAE_NPBGKPAK#Z
Is there something else which needs to be dine in case of linking a MFC DLL with a regular one, like adding AFX_EXT_ or something?
Kindly advise in this.
Thank you.
UPDATE
Seems all that was required was to toggle the flag set in Project Properties>>C/C++>>Language>>Treat wchar_t as a built in type to NO. I'd never bothered with the flag before, so didn't know. The Linker error was there...
OK. Now I've another problem. The toggling of wchar_t solved the problem of the DLL linking with another MFC DLL, but now my application cannot find the entry point in my DLL. In dependency walker, it shows a mismatch between CString which the application is sending, and the Unsigned Short..which my DLL is accepting ( as a result of thewchar_t turned off, presumably )
Assuming you correctly included the .lib file for the DLL (most of the time this is down to differences in the compiler settings. e.g. UNICODE setting).
Check that the .lib is actually being loaded by setting the 'Show Progress' Linker settings to VERBOSE.
Run DUMPBIN on the LIB file to check that the exported functions are the same as the ones the linker is trying to import.
ie
dumpbin /ALL mylib.lib > exports.txt
If the name decoration is slightly different that'll give you a clue as to the problem.
I'm trying to write some simple test code for the Crypto++ library for a project. I have yet to manage to get my own code to build though. It compiles fine, the problem comes in linking. I'm still pretty new to Visual Studios, but I'm using VS10. The errors I'm getting are:
1>sec_test.obj : error LNK2001: unresolved external symbol "public: virtual void __thiscall CryptoPP::DES::Base::ProcessAndXorBlock(unsigned char const *,unsigned char const *,unsigned char *)const " (?ProcessAndXorBlock#Base#DES#CryptoPP##UBEXPBE0PAE#Z)
1>sec_test.obj : error LNK2001: unresolved external symbol "public: virtual void __thiscall CryptoPP::DES::Base::UncheckedSetKey(unsigned char const *,unsigned int,class CryptoPP::NameValuePairs const &)" (?UncheckedSetKey#Base#DES#CryptoPP##UAEXPBEIABVNameValuePairs#3##Z)
I've tried everything I can find in the documentation in terms of linking. I've never linked against a DLL before, but these are the errors I get when I try to. If I try to do what I think is linking against the static library version, I get even more.
I should note, I'm trying to test pure DES at the moment. In particular, here are the API calls I'm making, just to be safe:
DES::Encryption DES_encrypt;
DES_encrypt.SetKey(key, 64);
DES_encrypt.ProcessAndXorBlock(plaintext, NULL, ciphertext);
DES::Decryption DES_decrypt;
DES_decrypt.SetKey(key, 64);
DES_decrypt.ProcessAndXorBlock(ciphertext, NULL, decrypted);
If anyone can help, or point me in the right direction, I'd be much obliged.
First thing to check is your project properties (right click on project, click Properties).
External libraries need to be specified in the Linker->Input->Additional Dependencies field, either by absolute path or in conjunction with the other VS path properties.
You can look in Linker->Command Line and check that the .lib files you want are actually being passed to the linker.
An alternate method is to turn off the Suppress Startup Banner option in the Linker->General options, and then check the build output to make sure it has what you want.
If you know that the libraries you want are being linked, another useful trick is to check the output of the strings command (in linux or cygwin) or dumpbin /HEADERS in the VS command prompt. You can look through the output of these commands for the symbol VS claims is missing to verify that it really is defined in the .lib file. Sometimes larger software packages have multiple .lib files, so this can help make sure you are linking the one that has the symbol you want.
Okay, here's the thing. I have all the IL files I need, namely
DevIL.dll
DevIL.lib
ILU.dll
ILU.lib
ILUT.dll
ILUT.lib
config.h
config.h.in
devil_cpp_wrapper.h
devil_internal_exports.h
il.h
ilu.h
ilu_region.h
ilut.h
ilut_config.h
My project directory looks like this, let's say my project's name is "Project1"
|-Debug---Project1.pdb
|
| |---Debug---[loads of files]
| |
| |---Glut---[OpenGL files]
| |
| |---IL---[all the files mentioned above]
|-Project1---|
| |---image.bmp
Project Folder---| |
| |---[header and .cpp files I made in the project]
| |
| |---[files produced by Visual Studio]
|
|-ipch---[unrelated stuff]
|
|-Project1.sln
|
|-[other files VS created]
I've put all the DevIL files in the IL folder, as mentioned, and I am sure I am using the unicode compatible versions of them, as I am using Unicode Character Set for the project. In my "Additional Dependencies" I have
ilut.lib; ilu.lib; DevIL.lib;
So, the dependencies are there, I know that's not the problem.
After all that, I am still getting linker errors, mainly LNK2019:unresolved external symbol__imp_ for all the IL functions.
What am I missing? It looks to me like maybe something to do with the project properties or the files themselves...maybe I missed a file?
EDIT: Here is the output messages
1>------ Build started: Project: Final Year Project, Configuration: Debug Win32 ------
1>Build started 29/4/2011 12:46:04 pm.
1>InitializeBuildStatus:
1> Touching "Debug\Final Year Project.unsuccessfulbuild".
1>ClCompile:
1> Main.cpp
1>c:\users\xxxx\desktop\final year project 0.2\final year project\main.cpp(152): warning C4390: ';' : empty controlled statement found; is this the intent?
1>c:\users\xxxx\desktop\final year project 0.2\final year project\main.cpp(141): warning C4101: 'alpha' : unreferenced local variable
1>ManifestResourceCompile:
1> All outputs are up-to-date.
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilInit#0 referenced in function "public: static void __cdecl Main::Init(int,char * *)" (?Init#Main##SAXHPAPAD#Z)
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilDeleteImages#8 referenced in function "public: static void __cdecl Main::DisplayScene(void)" (?DisplayScene#Main##SAXXZ)
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilGetData#0 referenced in function "public: static void __cdecl Main::DisplayScene(void)" (?DisplayScene#Main##SAXXZ)
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilConvertImage#8 referenced in function "public: static void __cdecl Main::DisplayScene(void)" (?DisplayScene#Main##SAXXZ)
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilGetInteger#4 referenced in function "public: static void __cdecl Main::DisplayScene(void)" (?DisplayScene#Main##SAXXZ)
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilLoadImage#4 referenced in function "public: static void __cdecl Main::DisplayScene(void)" (?DisplayScene#Main##SAXXZ)
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilBindImage#4 referenced in function "public: static void __cdecl Main::DisplayScene(void)" (?DisplayScene#Main##SAXXZ)
1>Main.obj : error LNK2019: unresolved external symbol __imp__ilGenImages#8 referenced in function "public: static void __cdecl Main::DisplayScene(void)" (?DisplayScene#Main##SAXXZ)
1>C:\Users\xxxx\Desktop\Final Year Project 0.2\Debug\Final Year Project.exe : fatal error LNK1120: 8 unresolved externals
1>
1>Build FAILED.
1>
1>Time Elapsed 00:00:01.93
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========
Since you added the build output, the answer is now easy: your linker errors have nothing to do with DevIL at all.
You need to link to SDL (Simple DirectMedia Layer).
Since SDL has a C interface, and - IIRC - doesn't require that the DLL uses the same heap as the application, the VC8 version of the "Development Libraries" should do fine (even if you use VC10). Just add SDL.lib to the "Additional Dependencies" and you should be fine.
EDIT
OK.
You're either
not linking against the required .lib files (DevIL.lib etc.) or
linking against corrupted/wrong .lib files
At least there is no other explanation I can think of.
The names mentioned in your build log (__imp__ilInit#0 etc.) are correct, and the current "DevIL SDK" (DevIL 1.7.8 SDK for 32-bit Windows) works fine with VC10 (I just verified it).
To assure you're linking against DevIL.lib etc. please put the following in your main.cpp file:
#pragma comment(lib, "DevIL.lib")
#pragma comment(lib, "ILU.lib")
#pragma comment(lib, "ILUT.lib")
To make sure you're linking against the correct version of those files, re-download the whole SDK and try again with the new files.
EDIT 2
Since I got half the reward, I feel I should be more helpful :)
One last thing you can try: enable verbose linker output to check if the linker finds the correct version of DevIL.lib. (If it didn't find any DevIL.lib, you would get an error LNK1104: cannot open file 'DevIL.lib' - and since you're not getting that message, that cannot be the problem.)
To enable verbose linker output, add the /VERBOSE switch (under Configuration Settings -> Linker -> Command Line -> Additional Options).
That will give you a ton of messages. Copy them into your favorite editor, and search for lines containing DevIL.lib. One of the lines should read Searching X:\path\to\DevIL.lib: - that's the path to the copy of DevIL.lib the linker is using. If that's not the path where you copied the files from the SDK you downloaded, you have found the problem.
And if there are no lines containing DevIL.lib, then the linker isn't even trying to locate it. However I've never seen #pragma comment fail, so if you indeed added those lines that almost surely cannot be the case.
BTW: please let me know if you managed to solve this. This is so strange that I really want to know what was going on :)
You need to tell the linker to link against the IL libs.
Project settings, Linker, Input
Make sure the directory the libs are in is in the Additional directorys field too.
I've noticed your config.h.in file should have .win extension because that it is in DevIL-SDK-x86-1.7.8.zip package. And there's no devil_cpp_wrapper.h file also.
Finally i solved this in this way:
Header files
config.h
config.h.win
devil_internal_exports.h
il.h
il_wrap.h
ilu.h
ilu_region.h
ilut.h
ilut_config.h
goes to VC include directory - all in one directory named IL (c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include\IL\ by default)
Liblary files
DevIL.lib
ILU.lib
ILUT.lib
goes to lib directory (c:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\lib\ by default)
DLL files
DevIL.dll
ILU.dll
ILUT.dll
goes to project dorectory (...\Project Folder\Project1\ in your case)
Then i added liblary files to project by right click on project->Properties->Linker->Input->Additional Dependencies (wrote just name of liblaries like ILU.lib)
In my project I just include IL\il.h, IL\ilu.h and IL\ilut.h
I think you may got wrong files by the way...
Just in case you never got this worked out, or anyone else has the same problem (like I did):
I had downloaded the 64-bit version of DevIL for my 64-bit Windows computer, but Microsoft Visual Studio (I was using Express) was the 32-bit version.
I downloaded the 32-bit version of DevIL and it worked!
I had the same problem. Seems like the pre-built binaries are swapped: I could link to the ones designated as non-unicode but they would utterly fail trying to use my non-unicode strings and return unicode strings. Try to build your own binaries from the source or use a previous version.
you should compare the function signatures that you see in your errors with the signatures you get with depends.exe (depedency walker). If they differ there may be a compiler-issue.
You may then try to compile with :
extern "C" {
// put your devils-include directives here ...
}
Nothing garantied of course , just a suggestion.
You may also check the 'Additional Library Directories' property on your 'Linker\General' page to see if (when used) it points to the right directory for your build (if you also added a path to the standard VC lib-directories their may be a conflict ,use either one but not both).
Another suggestion is to create a new project and do it all over again ,you may have made an ever so little mistake.
Good luck !
I had the same problem.
In my case it was problem with code in all devil`s .h files
#ifdef _WIN32
#if (defined(IL_USE_PRAGMA_LIBS)) && (!defined(_IL_BUILD_LIBRARY))
#if defined(_MSC_VER) || defined(__BORLANDC__)
#pragma comment(lib, "%LIBNAME%.lib")
#endif
#endif
#endif
after second #if code was deactivated.
i added #pragma comment(lib, "DevIL.lib") (and 2 more) into my main.h and linker errors dissapeared.
sorry for my bad english =[
I don't know if this question is still active, but since it has no chosen answer, I'll post this. I had what seems like the exact same problem with DevIL version 1.7.8. To fix it, I rolled back the version to 1.7.7 and used #undef _UNICODE before including the headers and #define _UNICODE afterwards. The project compiled without linker errors and worked without a hitch. On 1.7.8, the libraries seem to all be unicode, or at least they don't seem to support ascii very well. However, this may just be some weird compatibility issue with my computer as it does not seem to be a common problem
It might be that you have to declare some preprocessor variable to actually tell the compiler that you are importing symbol; I mean something related to __declspec( dllimport )
I did exactly as what Sarah said about the 32-bit or 64-bit Visual Studio versions. I'm on a 64-bit computer running a 32-bit Visual Studio 2012. I obtained this error when I used the x64 DevIL files. Getting the x86 version helped. Here's the basic steps I took to ensure it does run:
Right-click your project and go to Properties.
Under C/C++ > General, add DevIL's 'include' folder under Additional Include Directories.
Then under Linker > General, add DevIL's 'lib' folder (it should contain: DevIL.lib, ILU.lib and ILUT.lib) to Additional Library Directories. For x64 it may not contain a lib folder, it may be just the DevIL directory itself (for version 1.7.8 it was that case).
Also in Linker > Input, add those .lib file names into Additional Dependencies.
Now that should be all you need to do in the project properties. In the main.cpp you should include the appropriate header files and it should work when you initialize.
Example:
#include "IL/il.h"
#include "IL/ilu.h"
#include "IL/ilut.h"
int main(){
ilInit();
iluInit();
ilutRenderer(ILUT_OPENGL); //these are just to initialize
}
I get this error in visual studio and I don't know the reason. It doesn't even show the line number. Any clue?
Error 1 error LNK2028: unresolved
token (0A000041) "void __cdecl
free_img(struct Image *)"
(?free_img##$$FYAXPAUImage###Z)
referenced in function "double *
__cdecl calc_zernike_moments(struct Image const *,int,struct ZernikeBasis
const *)"
(?calc_zernike_moments##$$FYAPANPBUImage##HPBUZernikeBasis###Z) zernike_moments.obj TestLibrary
You have a routine
double * __cdecl calc_zernike_moments(struct Image const *foo,
int baz,
struct ZernikeBasis const *bar)
that calls a routine
void __cdecl free_img(struct Image *foo)
and you didn't supply the free_img() routine that matched to the linker.
free_img() is a function that is either defined in a .cpp file that you haven't included in the project, or it is in a DLL or static library that you haven't linked against. If it is the former, you need to search for the function in your source files and then add that .cpp file to the project. If it is the latter, then you need to identify which library provides free_img() and then locate the .lib file for that library. Then you can do this:
To add .lib files as linker input in the development environment
Open the project's Property Pages dialog box. For details, see Setting Visual C++ Project Properties.
Click the Linker folder.
Click the Input property page.
Modify the Additional Dependencies property.
(from http://msdn.microsoft.com/en-us/library/ba1z7822(VS.80).aspx)
You need to link the library. Where is the definition of free_img()?
You are just including the .h and not linking lib
The error is a linker error, not a compiler error, so there won't be a line number associated with it. Rather the error is telling you that your function calc_zernike_moments is calling another routine, free_img, that isn't defined in any of TestLibrary's compiled sources, so you need to provide it by other means. Typically what's missing here is the third-party library need be included in the project so the linker can bring in free_img's implementation.