problem compiling fromDll with 2.6.3 under WinXP & MSVC6 Topic is solved

[Widgets]

I'm trying to compile the updated fromDLL example from

www.dastur.me.uk/wx/wxDLL_VS7-1_ReallyWorks.zip

using MSVC 6.00

I've added the include paths and WXUSINGDLL to the fromDll project, but when I try to link that portion, I get the linker complaining:

LINK : fatal error LNK1104: cannot open file: "wxmsw26d_qa.lib"

and indeed I cannot find the file.

I've tried to make it with
nmake -f makefile.vcc SHARED=1 MONOLITHIC=1 BUILD=debug USE_QA=1
but nothing seems to happen and the library doesn't get built.

What am I missing or overlooking?

[Widgets]

After posting and thinking some more, I realized I should not use MONOLITHIC=1, but even without that, the library I seem to need does not get built.

[Dandel1984]

i would look at your files after reading this...

http://www.wxwindows.org/manuals/2.6.3/ ... slist.html

look at your wxwidgets directory where you find wxbase26 and find the file that has QA on it, because there should be no reason for it to exist, but it might be under a different name than your using.

[Widgets]

Again, thanks.
I had a look at the link and have also tried to compile this under MSVC6.0 as a release, figuring that the QA lib should not be needed - since it supposedly only contains wxDebugReport, but surprise, surprise, it now complains about wxmsw26_qa.lib not being found.

As you might have guessed it is all part of the same search for a solution to using wxwidgets from a dll.

[Widgets]

OK, I've resolved that issue.

By looking at the makefile.vc I've found that I need to use
nmake -f makefile.vc SHARED=1 USE_GUI=1 USE_QA=1

Now at least the libs etc are made, but now I get other errors - unresolved externals. I'll investigate that part and see how far I get.

[Widgets]

Getting closer and closer

I had assumed WXUSINGDLL needed to be defined only for the main app.

As a trial I defined it also for the dll and lo and behold the DEBUG version actually compiles without errors and once I make all of the necessary wxWidget dlls accessible ot the application, it runs and does its thing.

The RELEASE version still has an undefined symbol:

FromDLL.obj : error LNK2001: unresolved external symbol "__declspec(dllimport) public: void __thiscall wxStringData::Free(void)" (__imp_?Free@wxStringData@@QAEXXZ)

According to a comment in string.cpp the code for this function is omitted in certain cases when compiling under Visual C++ - but no info re possible timeframe for or means of resolution

Anyone with any suggestions?

[dsilvia]

As per C:\wxWidgets-2.6.3\src\common\string.cpp

Code: Select all

// ===========================================================================
// wxStringData class deallocation
// ===========================================================================

#if defined(__VISUALC__) && defined(_MT) && !defined(_DLL)
#  pragma message (__FILE__ ": building with Multithreaded non DLL runtime has a performance impact on wxString!")
void wxStringData::Free()
{
    free(this);
}
#endif

Which means that your wxWidgets libraries in vc_lib and your current code you're working with in Visual Studio 2005 must be in synch. If one qualifies to have the subject member function defined and included, so must the other, and the converse is true.

I had built my vc_lib using DialogBlocks which defaults to DLLs, so, the above code was never compiled into my wxWidgets libraries for vc_lib. Now, I went to Visual Studio 2005 Express to build some existing code and it defaulted to /MT. This meant that the above code was compiled into my application, so up popped the unresolved references. On changing to /MD everything was hunkey-dorey!


HTH,
Dave S.