[solved] trouble linking libtiff with vc++

[katz0r]

Dear Qt Fans,

I am trying to link libtiff to a Qt Project using QtCreator and the compiler from Visual Studio 2012, 64bit. Libtiff compiled just fine using the supplied makefile.vc

The arguments in the .pro file are

@INCLUDEPATH = -I"..\tiff-4.0.3\libtiff" -I"..\tiff-4.0.3\port"
LIBS += -L"..\tiff-4.0.3\libtiff" # ..\tiff-4.0.3\port\libport.lib ..\tiff-4.0.3\libtiff\libtiff.lib ..\tiff-4.0.3\libtiff\libtiff_i.lib@

and the linker seems to find the corresponding .lib files. Yet, the linker cant resolve "TIFFOpen" "TIFFClose" "TIFFWriteScanline" "TIFFSetField" external symbols.
I can however, find the symbols in the lib file. dumpbin yields

@ 010 00000170 SECT5 notype () External | _TIFFClose
...
008 00000000 SECT3 notype Static | ?module@?1??TIFFOpen@@9@9 (TIFFOpen'::2'::module)
00D 0000000C SECT3 notype Static | ?module@?1??TIFFOpenW@@9@9 (TIFFOpenW'::2'::module)
...
034 000000C0 SECT5 notype () External | _TIFFOpen
035 000001B0 SECT5 notype () External | _TIFFOpenW@

I suspect that some build argument for Qt is different so the name mangling schemes are not compatible. What are your ideas? I have read something about wchar_t being a native type or not. Or could it be static vs dynamic linking?

thanks!
Martin

[SGaist]

Hi,

Out of curiosity, why do you need to link against libtiff ? Tiff support is already implemented in Qt

[katz0r]

Hi, thanks for the answer!

Yes, tiff is supported by Qt, but i need to save data with 16bit per sample. I think thats not possible with the built in tiff routines. (I'd be glad to be corrected here)

[SGaist]

AFAIK you're correct about the 16bit.

One trick that you could use is to include the tiff.pri from Qt's sources in your project so it will be built/linked with your code. Not the most economic way but so you are sure to have a working libtiff on windows (and no need to install another one)

[katz0r]

Dear SGaist,

thanks for the hint, it worked! libtiff.pri produces the tiff_* objs in the build directory and links without problems.

Sorry for the late reply, I didnt get back to this earlier.