I have a C static library compiled using MinGW. A .a file is generated and then used in a Visual Studio project. The static library uses SecureZeroMemory internally. The Visual Studio project runs into an issue where it cannot resolved RtlSecureZeroMemory, which is the function behind the SecureZeroMemory macro.
LNK2019 unresolved external symbol RtlSecureZeroMemory referenced in function static_lib_memset_func
I would have thought that this function would have been in one of the libraries that Visual Studio adds by default (ex. kernel32.dll). But, using dependency walker, I cannot find this symbol.
What should my project include to get this working?
The function inside the static library was also marked inline when it called SecureZeroMemory. By removing the inline keyword, the problem went away. I think it has something to do with the fact that the RtlSecureZeroMemory was annoted as extern inline __attribute__((__gnu_inline__)) and my function was also inlined.
Related
I am working on a big MASM project (I've Compiled my MASM code using the ML compiler under VS 2019) , and I would like to call a C function I wrote, within my MASM code. I googled it a lot , but I couldn't find anything useful. How can I achieve that?
When I just tried to add my C source-code to the project and rebuild it , I got a bunch of linking errors (LNK2019) , like these:
LNK2019 unresolved external symbol __CrtDbgReport referenced in function __CRT_RTC_INIT
LNK2019 unresolved external symbol __CrtDbgReportW referenced in function __CRT_RTC_INITW
LNK2019 unresolved external symbol ___stdio_common_vsprintf_s referenced in function __vsprintf_s_l
Here is a screenshot of the errors window
Answering my question
I've finally figured out a way to do this.
Create a Static library (.lib) from your C/C++ module.
Properies -> Project Defaults -> Configuration Type -> change to .lib
and then, In your masm code , add these lines:
includelib your_generated_lib.lib
(Be sure to add your lib file to the directory of your masm code)
and add prototypes to your functoins like this:
function_name PROTO C :DWORD ;(Just an Example )
Hope it helps,
Omer
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\"
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
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.
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.