It has been about a year since I wrote any .dll plugins that use LibCurl, but I decided to start on another one tonight. Unfortunately, I have been combating the same linker errors for almost 4 hours now, and I am completely lost.
I am statically building LibCurl, and it appears to be fine for the most part, except I am getting the following linker errors.
1>MSVCRT.lib(MSVCR90.dll) : error LNK2005: _calloc already defined in memoverride.obj
1>MSVCRT.lib(MSVCR90.dll) : error LNK2005: _realloc already defined in memoverride.obj
1>MSVCRT.lib(MSVCR90.dll) : error LNK2005: _free already defined in memoverride.obj
1>MSVCRT.lib(MSVCR90.dll) : error LNK2005: _malloc already defined in memoverride.obj
1>MSVCRT.lib(MSVCR90.dll) : error LNK2005: __strdup already defined in memoverride.obj
1>MSVCRT.lib(MSVCR90.dll) : error LNK2005: __malloc_crt already defined in memoverride.obj
I have tried...
1) Reorganizing my included libs due to MSDN saying LNK2005 was caused by this.
2) Rebuilding the LibCurl lib through MSVC Application, then through the Command-Line tool.
3) Excluding the libs that are causing issues.
and a bunch of other things that I cannot even remember now. Can anyone help me out with some information as to how I can solve these?
Problem was my .dll was /MT while the libcurl was /MD. Also, I had initially blocked "libcmt", so when I was switching libcurl to /MT, it was spewing errors.
Related
I have inherited a C++ solution with 3 projects, one compiling to a .DLL, the other two to .EXEs . The DLL builds on its own fine, but the other two, when built, produce around 65 LNK2005 errors, the majority of which are referencing the same .obj file, as shown in the log exert below:
Linking...
Function.obj : warning LNK4075: ignoring '/EDITANDCONTINUE' due to '/OPT:ICF' specification
Function.obj : error LNK2005: _ReadLocalRegister already defined in Function.obj
Function.obj : error LNK2005: _getSource already defined in Function.obj
Function.obj : error LNK2005: _SendLogEvent already defined in Function.obj
Function.obj : error LNK2005: _DebugMsg already defined in Function.obj
Function.obj : error LNK2005: _MyInformationMsg already defined in Function.obj
MyNTService.obj : error LNK2005: "public: __thiscall CMyNTService::CMyNTService(void)" (??0CMyNTService##QAE#XZ) already defined in MyNTService.obj
MyNTService.obj : error LNK2005: "public: virtual void __thiscall CMyNTService::OnStop(void)" (?OnStop#CMyNTService##UAEXXZ) already defined in MyNTService.obj
MyNTService.obj : error LNK2005: "public: void __thiscall CMyNTService::SaveStatus(void)" (?SaveStatus#CMyNTService##QAEXXZ) already defined in MyNTService.obj
....and so it goes on!
I am a C# coder, only basic C++ knowledge, so I am lost with this. The solution is an 15 year old C solution I am attempting to rebuild as a C++ solution in VS2008. I have managed to build it once, nothing has changed, but perhaps some config settings have changed since then.
Does anyone have ideas where I could start to look...?
Many thanks!
It sounds like you're missing inclusion guards on the header file for that object.
Add:
#ifndef SomeUniqueName
#define SomeUniqueName
//Code goes here.
#endif
Wrapping the code in the header file. The compiler will go through that header file many times when processing your code as it's included in many places (most likely). The inclusion guards stop redefinition of things that have already been defined on previous passes.
PS: It also might help to do a "make clean". Makefiles can be finnicky especially if not made 100% right and sometimes when dependencies are off you need to clean before rebuilding.
in msvc110 (2012), I encountered the same error and the only workaround i found was to create a class and a separate DLL for the recurrent functions I used in the different files.
Here's the link to do so.
Cheers
Hi
I have project In VC++ 2008
this project compile in debug mode without error
but when I try to build it in release mode I get below linking erorr.
1>Linking...
1>LIBCMTD.lib(dbgheap.obj) : error LNK2005: __heap_alloc already defined in LIBCMT.lib(malloc.obj)
1>LIBCMTD.lib(dbgheap.obj) : error LNK2005: __recalloc already defined in LIBCMT.lib(recalloc.obj)
1>LIBCMTD.lib(dbgheap.obj) : error LNK2005: __msize already defined in LIBCMT.lib(msize.obj)
1>LIBCMTD.lib(malloc.obj) : error LNK2005: _V6_HeapAlloc already defined in LIBCMT.lib(malloc.obj)
1>LIBCMTD.lib(dbghook.obj) : error LNK2005: __crt_debugger_hook already defined in LIBCMT.lib(dbghook.obj)
1>LIBCMTD.lib(sbheap.obj) : error LNK2005: ___sbh_pHeaderDefer already defined in LIBCMT.lib(sbheap.obj)
1>LIBCMTD.lib(sbheap.obj) : error LNK2005: __get_sbh_threshold already defined in LIBCMT.lib(sbheap.obj)
1>LIBCMTD.lib(sbheap.obj) : error LNK2005: __set_sbh_threshold already defined in LIBCMT.lib(sbheap.obj)
1>LIBCMTD.lib(sbheap.obj) : error LNK2005: __set_amblksiz already defined in LIBCMT.lib(sbheap.obj)
1>LIBCMTD.lib(sbheap.obj) : error LNK2005: __get_amblksiz already defined in LIBCMT.lib(sbheap.obj)......
how I can fix it?
thanks.
You're mixing VS runtimes - Make sure the "Project Properties/C++/Code Generation/Run-time Library" setting is the same for your project and all libraries you link to.
I had the same problem as you. Reason of this problem is that Linker include a lot of libraries that you dont see (for example you will include windows.h, it includes windef.h and so on...). And because these files are not idiot-proof written (#ifndef is missing) linker will try to #define same thing more times than once - problem.
My solution was setting this field:
Project Properties -> Linker -> Input -> Ignore specific library
to "libcmt.lib"
With this your linker will ignore also in release configuration that problematic library that is included by default and everything should work.. :-)
Have a nice day.. :-)
P.S. If you want to avoid these linker misunderstandings, keep configuring project not in debug or release configuration, but in "All configuration". This option is on left upper corner of project configuration.
You are linking a .obj or .lib file that was compiled in the Debug configuration. Best thing to do is to ensure that file is built in the Release mode as well. Second best is to tell the linker to ignore the request to link to libcmtd.lib. Project + Properties, Linker, Input, Ignore Specific Library = libcmtd.lib. But only do this if you can't get the Release build of a .lib after trying mightily.
you can delete preprocessor definition "DEBUG" to solve your issue
I ran into to similar problem and it was all to do with whether libraries you include build with right end state. If you build a program in release mode and pointed to *.lib files that compiled in debug mode. its going to give you symbol miss match errors. Specially if your program build fines in debug mode or vise versa.
This might not exactly what your problem is but good information for someone who ran into same thing as i did.
You probably have defined all the link information in the "Debug" configuration. Which means you need to either redefine it for "Release" or move it to the "All Configurations" so its shared.
So I have a Visual Studio 2010 project that uses external libraries and in order to get it compile without LNK2005 I had to juggle arround with the order of the libraries in the linker settings.
I got it to compile fine in release mode, but for whatever reasons I don't manage to get it to compile without LNK errors in debug.
Is there no way to generally ignore LNK2005 and tell the linker to simply use whatever he encounters first?
Thanks!
//edit: here are some of the errors output of the PARTICULAR problem. however I already tried to solve that in different ways with each solution giving me different linker problems. hence i'm looking for general solution to ignore LNK2005
Error 7 error LNK2005: "private: __thiscall type_info::type_info(class type_info const &)" (??0type_info##AAE#ABV0##Z) already defined in Libcmtd.lib(typinfo.obj)
...\msvcprtd.lib(MSVCP100D.dll)
Error 8 error LNK2005: "private: class type_info & __thiscall type_info::operator=(class type_info const &)" (??4type_info##AAEAAV0#ABV0##Z) already defined in Libcmtd.lib(typinfo.obj)
...\msvcprtd.lib(MSVCP100D.dll)
Error 9 error LNK2005: _exit already defined in Libcmtd.lib(crt0dat.obj)
...\msvcprtd.lib(MSVCP100D.dll)
Error 10 error LNK2005: __invalid_parameter already defined in Libcmtd.lib(invarg.obj)
...\msvcprtd.lib(MSVCP100D.dll)
...
Error 37 error LNK1169: one or more multiply defined symbols found
You may try the linker-option /FORCE (Force File Output in the Linker General tab of the Project Properties). This will force the linker to create a exe/dll even when such errors occur. But its left to you to find out if this exe does work at all or even correctly. After all i would not recommend this strategy.
Linker errors can sometimes be tedious to solve, but usually it has to be done only after migrating or setting up a project. This may take quite a while - it sometimes took me more then a day, but it should be done properly.
You absolutely must not ignore linker errors, ever! A linker is telling you that it's confused about a symbol that's defined in multiple places - where should it take the definition from? Do you really want it to be arbitrary? What about when you change your code and the linker randomly decides to take the other definition which might suddenly break your code?
Instead of fighting the tool, correct your code so that it compiles and links without errors. This MSDN article has some information on fixing it, along with links for more information.
I have a Visual Studio 6 workspace I'm trying to convert to a Visual Studio 2008 solution. The output of said solution is a .dll. It has to be a .dll and it needs to statically link MFC as I can't redistribute MFC to existing customers.
The solution consists of three projects, say A, B, C. C is the Active Project, outputs the .dll and depends on B. B outputs a .lib and depends on A. A outputs a .lib.
In the General configuration properties I have A and B set to Static Library (.lib) and C set to Dynamic Library (.dll). All three projects are set to "Use MFC in a Static Library." Also, all three projects are set to "Multi-threaded" for Runtime Library and none of them have _AFXDLL defined.
Everything builds correctly up until the final linking stage where I see this:
1>nafxcw.lib(wincore.obj) : error LNK2005: _IsPlatformNT already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _InitMultipleMonitorStubs already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _xGetSystemMetrics#4 already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _xMonitorFromPoint#12 already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _xMonitorFromRect#8 already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _xMonitorFromWindow#8 already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _xGetMonitorInfo#8 already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _xEnumDisplayMonitors#16 already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _xEnumDisplayDevices#16 already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_pfnGetSystemMetrics already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_pfnMonitorFromWindow already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_pfnMonitorFromRect already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_pfnMonitorFromPoint already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_pfnGetMonitorInfo already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_pfnEnumDisplayMonitors already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_pfnEnumDisplayDevices already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_fMultiMonInitDone already defined in A.lib(Globals.obj)
1>nafxcw.lib(wincore.obj) : error LNK2005: _g_fMultimonPlatformNT already defined in A.lib(Globals.obj)
1>nafxcw.lib(viewprnt.obj) : error LNK2005: "public: virtual int __thiscall CPrintingDialog::OnInitDialog(void)" (?OnInitDialog#CPrintingDialog##UAEHXZ) already defined in B.lib(ImagePropertiesDlg.obj)
1>nafxcw.lib(viewprnt.obj) : error LNK2005: "public: __thiscall CPrintingDialog::CPrintingDialog(class CWnd *)" (??0CPrintingDialog##QAE#PAVCWnd###Z) already defined in B.lib(ImagePropertiesDlg.obj)
1>nafxcw.lib(viewprnt.obj) : error LNK2005: "public: virtual void __thiscall CPrintingDialog::OnCancel(void)" (?OnCancel#CPrintingDialog##UAEXXZ) already defined in B.lib(ImagePropertiesDlg.obj)
I've Googled the problem to death and seen other people with a similarish issue, but can't seem to solve it. I tried adding nafxcw.lib to the Ignored libraries for C, but that turned this batch of linker errors into 1500+ unresolved symbol errors. I can get it to compile/link if I make it dynamically link MFC, but like I said, I need it to statically link. I feel like I'm missing something rather simple but can't seem to wrap my head around it. Any and all random thoughts and ideas will be greatly appreciated.
As is often the case, the solution turned out to be so mundane and obvious, I'm still kicking myself for banging my head on it for so long.
Basically, project A referenced above was not a project I directly pulled from the old VS6 workspace, but rather a project that had previously been converted by another team for use in another application. I assumed it was functionally equivalent to the original one, but that is very much not the case. These linking errors are actual, valid multiply defined linking errors. When I started digging in, I found that the first batch of errors was from including multimon.h in project A (something I don't even need, just removed it) and the second batch is from a class that is actually defined in both A and B.
Like I said, I'm still groaning over here, but at least I should be able to fix my problem now. Thanks for the help and always remember to NEVER assume ANYTHING.
When you tried ignoring the nafxcw library, did you add it back in to try to force a link order as suggested by this KB article? While your problem isn't an exact fit it may be related. Perhaps things could be resolved by monkeying with the link order.
Here is My Scenario.
I have an Existing Solution in visualstudio which contains 15 projects.
in some project i need to use managed c++ extensions. So first i have a workaround for sample solution contains 4 projects in those i have maintained dependencies b/w them.
and my solution is builded also.
I apply the same procedure to existing solution by adding extra project which contains managed code.so that i enable CLR in calling project(from where i call new added project methods from existing ex:demoproj) as well as project which contains main().and change the runtime from /mtd(existing one contains /mtd) to /mdd.
when i build the demoproj it builds success fully. But when i building project which contains main() it gives lot of errors like
LINK : warning LNK4098: defaultlib 'MSVCRTD' conflicts with use of other libs; use /NODEFAULTLIB:library
LIBCMTD.lib(winxfltr.obj) : error LNK2005: __XcptFilter already defined in MSVCRTD.lib(MSVCR80D.dll)
LIBCMTD.lib(invarg.obj) : error LNK2005: __invalid_parameter already defined in MSVCRTD.lib(MSVCR80D.dll)
LIBCMTD.lib(invarg.obj) : error LNK2005: __invoke_watson already defined in MSVCRTD.lib(MSVCR80D.dll)
LIBCMTD.lib(crt0.obj) : error LNK2005: _mainCRTStartup already defined in MSVCRTD.lib(crtexe.obj)
LIBCMTD.lib(fclose.obj) : error LNK2005: _fclose already defined in MSVCRTD.lib(MSVCR80D.dll)
LIBCMTD.lib(printf.obj) : error LNK2005: _printf already defined in MSVCRTD.lib(MSVCR80D.dll)
LIBCMTD.lib(mbstowcs.obj) : error LNK2005: _mbstowcs already defined in MSVCRTD.lib(MSVCR80D.dll)
I found this is happend because of using /clr option i think any idea???
But this case is not happend for my test solution.How to resolve this
Any help is greatly appreciated
All the dlls you link to using import libraries must have the same setting as the application for how you link to the runtime library. The errors are showing that you are mixing use of the runtime as a .dll (MSVCRTD) and as a .lib (LIBCMTD).