While integrating the Nurbs library (http://www.rhino3d.com/opennurbs) into my project, I run into the following linking error with the library zlib.
1>zlib.lib(deflate.obj) : error LNK2019: unresolved external symbol _zcfree referenced in function _z_deflateInit2_
1>zlib.lib(inflate.obj) : error LNK2001: unresolved external symbol _zcfree
1>zlib.lib(deflate.obj) : error LNK2019: unresolved external symbol _zcalloc referenced in function _z_deflateInit2_
1>zlib.lib(inflate.obj) : error LNK2001: unresolved external symbol _zcalloc
I checked the function
z_deflateInit2
in the file deflate.c from ZLIB source code,
and guess that this function cannot find the implementation of the two functions zcfree adn zcalloc. The reason is that the Nurbs library customize the function zcfree and zcalloc, which is done in two steps.
Cusomize zcalloc and zcfree in the the Nurbs library code.
opennurbs_zlib.h
extern "C" {
voidpf zcalloc (voidpf, unsigned, unsigned);
void zcfree (voidpf, voidpf);
}
These two functions are implementated in the file opennurbs_zlib_memory.cpp as following
#define voidpf z_voidpf
voidpf zcalloc (voidpf, unsigned items, unsigned size)
{
return oncalloc(items, size);
}
void zcfree (voidpf, voidpf ptr)
{
onfree(ptr);
}
Compile the ZLIB library with the flag: MY_ZCALLOC and Z_PREFIX
As I checked, both these two steps are done, but why I still got the linking error.
Could you give me some advices?
Thanks so much!
Update:
#Dale Lear: thanks for your support. But my situation is different. Instead if linking with the opennurbs.lib, I tried to integrate the source code of opennurbs into my project (like the surface module of point cloud library: http://www.pointclouds.org/blog/trcs/moerwald/). I build zlib from the project zlib in opennurbs solution. This zLib is built with the modified zconfig.h (Z_PREFIX and Z_MYCALL, i guess so, is defined). This means that the function zfree and zalloc is still waiting for implementation. But why does ZLib does not take zcfree() and zcalloc from opennurbs_zlib_memory.cpp. I don't understand why does it take.
From your description and the error log you provided, I'm guessing that the situation is:
1) You are building a Windows program using some version of Microsoft's C++ compiler.
2) You want to statically link with zlib.lib
3) You want to statically link with opennnurbs_staticlib.lib
I cannot determine what version of Microsoft's C++ compiler or opennurbs you're using.
If you are using the latest public release of opennurbs (version 2013-07-11), then the zcfree() and zcalloc() functions are defined in the file opennurbs_zlib_memory.cpp.
If you build opennurbs_staticlib.lib using the opennurbs_staticlib.vcxproj project file that is included with the source code, it will compile opennurbs_zlib_memory.cpp and include the zcfree() and zcalloc() functions in it in opennurbs_staticlib.lib. If you build zlib using the zlib code and zlib/zlib.vcxproj file that is included with opennurbs 2013-07-11, then it will be built with all the necessary defines and you will have two static libraries, zlib.lib and opennurbs_staticlib.lib, that link with all dependencies resolved.
If you are using customized project files, the first thing to check is that you are statically linking the results of compiling opennurbs_zlib_memory.cpp in some way.
If you want to use opennurbs as a DLL, I'd suggest building opennurbs.dll with the opennurbs.vcxproj project file that comes with the source code. This opennurbs.dll will statically include zlib.lib when it links and you do not have to link with anything except the resulting opennurbs.lib to use the DLL version.
Does this help?
-- Dale Lear
Related
I'm writing a DLL for an existing application. The DLL is designed to interface to commercial software who's functionality can be enhanced by adding a user defined feature with a DLL.
My DLL compiles and the application can utilize the features, but I want to debug it. It is difficult for me to attach to the process and debug when the commercial software is calling the DLL. Instead, I'd like to build separate code to test the DLL.
All the examples I can find w/DLL's are for C# or C++. I can't quite understand how to do this in C. I seem to be stuck at importing the DLL or referencing the library in the linker.
I've inserted:
__declspec(dllimport) int UserDefinedSurface4(USER_DATA *UD, FIXED_DATA4 *FD);
but I get:
LNK2019 unresolved external symbol "__declspec(dllimport) int __cdecl UserDefinedSurface4(struct USER_DATA *,struct FIXED_DATA4 *)" (__imp_?UserDefinedSurface4##YAHPEAUUSER_DATA##PEAUFIXED_DATA4###Z)
Following advice for C# and C++, I've added a path to the DLL in my project using: Properties->Linker->Input->Additional Dependencies with an explicit path: "D:......\mydll.lib" (that seems kind of brittle... is this right or should I use a relative path or ...?)
Furthermore, I also inserted:
#pragma comment(lib, "D:\\...\\mydll.lib")
and I have included the project with the DLL in my references. What's missing?
Your dll import looks fine.
Check the name of the exported function. Good tool for this task is "Dependency Walker". If your dll compiled as C++, function name can be mangled. To prevent name mangling your export definition in DLL project should be:
extern "C" __declspec(dllexport) int UserDefinedSurface4(USER_DATA *UD, FIXED_DATA4 *FD);
In your application specify Linker -> Additional Library Directories to your library directory and in Linker -> Input specify additional dependency mydll.lib. After that check Linker -> Command Line parameter, it should contains:
"mydll.lib" /LIBPATH:"d:\yourlibrarydir\"
Just to be clear - I have searched the depths of the internet and back for information on how to do this
I'm looking for assistance setting up pthread_Win32 to work with Visual Studio 2005. I'm programming in C, and I have a number of multithreaded assignments to write using pthread.h. However, since pthread is native to unix, I have to write all of my code, ftp it, and then ssh to my class' remote unix system to run it. It makes development take so much longer, and it's incredibly inefficient. I'd love (more than anything) to be able to get this working on my win32 machine, so I can develop in visual studio as I've been doing for quite some time.
I've installed the pthread.lib file and pthread.h file into the respective lib/header directories, where all of the other files are. The DLL on the other hand (the actual library), I've placed in c:\windows\system32. I've tried to add the DLL as a dependency (right click project -> references -> Add new reference), but as others have stated, all I get is a blank dialogue box with no option to add any DLL files or anything. It seems to recognize the header file, but I get these errors when I compile:
1>Linking...
1>main.obj : error LNK2019: unresolved external symbol _imp_pthread_join referenced in function _main
1>main.obj : error LNK2019: unresolved external symbol _imp_pthread_create referenced in function _main
1>main.obj : error LNK2019: unresolved external symbol _imp_pthread_exit referenced in function _fcount
From my research, I've determined that this is a problem with the DLL, and I'm assuming it can't find the definitions of the functions I've referenced in my code. I've searched high and low and I can't seem to figure out any way to overcome this problem. I've added the directories of the lib/header files to my linker, just in-case, but that didn't solve the issue. I need to do something, in visual studio, to specify that I need pthreadVC2.dll as a project dependency - and it seems to be impossible (and extremely frustrating) at this point.
Any words of wisdom?
Thank you very much
I have been through this problem recently.
It appears that the __imp__ prefix is prepended to the function name in case pthread.h is included in dynamic linking mode.
Simply add the PTW32_STATIC_LIB define to your project or your source code before including pthread.h should solve the issue.
#define PTW32_STATIC_LIB
#include <pthread.h>
Although, I am not completely over as Visual Studio now trys to link with the _[FuncName] instead of [FuncName]
In visual studio, function seems to be declared differently wether you are going to link them statically (.lib) or dynamically (.dll).
To define a function you will link dynamically :
__declspec (dllimport) int myFunc(int myArgs) ;
To define function you are exporting for dynamic linking :
__declspec (dllexport) int myFunc(int myArgs) ;
And the simpliest, to define a function you will link statically:
int myFunc(int myArgs) ;
[EDIT]
I am going on my investigations and went through this on MS help center.
It seems that to avoid the _[FuncName] effect it is required to define a static linked library function by the following:
int __cdecl myFunc(int MyArgs) ;
Have you added pthreadVC.lib (or whichever particular lib you need) to the project property:
Linker/Input/Additional Dependencies
It's not enough to just have the lib file in a particular directory, the linker needs to be told to use it as an input.
Just adding pthreadVC2.lib to linker list is not suffiecient.
You also have to add addtional lib like pthreadVCE2.lib and pthreadVSE2.lib.
I am facing same issue but then I resolved it through adding these files.
I looked for similar problems, but the only topic might be the one on the use of a library, which I would avoid... here is my issue, I get this error:
1>Signal generator.obj : error LNK2001: unresolved external symbol "double __cdecl findMaxModulus(double *,int)" (?findMaxModulus##YANPANH#Z)
I am using visual studio professional 2008 to develop a c program. I have a main file and another file with all the functions I wrote, myFunctions.h/c. The problem is that these errors do not come out when I include "myFunctions.c", while they come out when I include "myFunctions.h".
i am doing what i remember from university (i am much more into matlab now), which is
/* Home-made includes */
#include "myType.h"
#include "myFunctions.h"
just after the inclusion of the othe headers (stdlib, math, etc...)
any guess? thank you
The error means the linker could not find the function. This most likely means that you aren't compiling your myFunctions.c file at all. Make sure it's added as a "source file" to the project in Visual Studio.
If you want to try on gcc try to compile both .c files same like this below:
gcc -Wall main.c myfunction.c -o final.out
You are missing the other .c file.So in the linking phase linker could not resolve the external symbol (which is your function). Try as I said.
For Visual Studio: You need to check whether all the source files are checked to make a build. there is an option to include number of files from the several source files.
I'm completely stumped on how to get FreeType 2.4.8 compiled as a static lib and usable from within my D application in Windows. I've tried running it over with objconv, coff2omf, and trying extern(C)/extern(System), etc. but nothing seems to work. I'm getting symbol not found errors, access violations and just a bunch of unhelpful errors.
How can I work around this? Am I correct in using pragma lib to link to my static libraries, and how do I reliably convert COFF static libs to OMF which DMD/Optlink can use?
EDIT: Some examples of what I've tried doing:
Compiling the FreeType source with VS 2010 as a static lib, linking in my D code with pragma lib. (Returned a "library format unknown" type error)
Same as above, but converting to OMF format using objconv and then trying to link with pragma lib. (Linked successfully, but still not able to call functions.)
Compiled a DLL of the FreeType source, ran it through implib to create an import library, tried linking with pragma lib. (Linked successfully, but unable to to call any functions due to "attempt to privileged function" or "access violation" errors)
I've tried defining function prototypes as all of: extern(System), extern(C), and extern(Windows). The first and third mangle the functions names of the extern-ed functions such that they don't match the static libraries, and the second compiles, but I get access violations during runtime when I actually try and call the functions.
I'm able to get it working via dynamic libraries and symbol loading, but I'd much prefer to not require a bunch of external dependencies when deploying my project.
I'm pretty sure Derelict2 has FreeType bindings: http://www.dsource.org/projects/derelict (See DerelictFT).
Yes, you will need extern(System) in your .d files with FT function declarations.
Static library a collection of object files. So no need for any kind of conversion (omf2coff, etc). DMD accepts a static libraries as arguments, so simple dmd file1.d file2.d C:/path/to/freetype.lib should work.
Edit:
I was wrong. Apparently I needed to read some documentation about the COFF2OMF.
Quote: The Microsoft COFF format apparently changed with Visual C++ 6.0. To use coff2omf on a .lib file with the newer format, use Microsoft's linker to convert the file to the earlier COFF format:
link /lib /convert freetype.lib
So, judging by the statement above you need to perform 2 steps.
First use the Microsoft's linker to convert static library you made with the VisualStudio (in COFF format) to the old COFF format as described above.
Now execute coff2omf freetype.lib to convert the static library into the OMF format.
It should now be ready to be used with the DMD the way described originally in my post.
Just to be clear - I have searched the depths of the internet and back for information on how to do this
I'm looking for assistance setting up pthread_Win32 to work with Visual Studio 2005. I'm programming in C, and I have a number of multithreaded assignments to write using pthread.h. However, since pthread is native to unix, I have to write all of my code, ftp it, and then ssh to my class' remote unix system to run it. It makes development take so much longer, and it's incredibly inefficient. I'd love (more than anything) to be able to get this working on my win32 machine, so I can develop in visual studio as I've been doing for quite some time.
I've installed the pthread.lib file and pthread.h file into the respective lib/header directories, where all of the other files are. The DLL on the other hand (the actual library), I've placed in c:\windows\system32. I've tried to add the DLL as a dependency (right click project -> references -> Add new reference), but as others have stated, all I get is a blank dialogue box with no option to add any DLL files or anything. It seems to recognize the header file, but I get these errors when I compile:
1>Linking...
1>main.obj : error LNK2019: unresolved external symbol _imp_pthread_join referenced in function _main
1>main.obj : error LNK2019: unresolved external symbol _imp_pthread_create referenced in function _main
1>main.obj : error LNK2019: unresolved external symbol _imp_pthread_exit referenced in function _fcount
From my research, I've determined that this is a problem with the DLL, and I'm assuming it can't find the definitions of the functions I've referenced in my code. I've searched high and low and I can't seem to figure out any way to overcome this problem. I've added the directories of the lib/header files to my linker, just in-case, but that didn't solve the issue. I need to do something, in visual studio, to specify that I need pthreadVC2.dll as a project dependency - and it seems to be impossible (and extremely frustrating) at this point.
Any words of wisdom?
Thank you very much
I have been through this problem recently.
It appears that the __imp__ prefix is prepended to the function name in case pthread.h is included in dynamic linking mode.
Simply add the PTW32_STATIC_LIB define to your project or your source code before including pthread.h should solve the issue.
#define PTW32_STATIC_LIB
#include <pthread.h>
Although, I am not completely over as Visual Studio now trys to link with the _[FuncName] instead of [FuncName]
In visual studio, function seems to be declared differently wether you are going to link them statically (.lib) or dynamically (.dll).
To define a function you will link dynamically :
__declspec (dllimport) int myFunc(int myArgs) ;
To define function you are exporting for dynamic linking :
__declspec (dllexport) int myFunc(int myArgs) ;
And the simpliest, to define a function you will link statically:
int myFunc(int myArgs) ;
[EDIT]
I am going on my investigations and went through this on MS help center.
It seems that to avoid the _[FuncName] effect it is required to define a static linked library function by the following:
int __cdecl myFunc(int MyArgs) ;
Have you added pthreadVC.lib (or whichever particular lib you need) to the project property:
Linker/Input/Additional Dependencies
It's not enough to just have the lib file in a particular directory, the linker needs to be told to use it as an input.
Just adding pthreadVC2.lib to linker list is not suffiecient.
You also have to add addtional lib like pthreadVCE2.lib and pthreadVSE2.lib.
I am facing same issue but then I resolved it through adding these files.