Linker errors (LNK2005) in Windows using Visual Studio

Question

I'm trying to build a project in Windows using VS2012 (2010 also available) that includes FTGL, which depends on FreeType.

When I try to build my project, I see a large number of the following LNK2005 errors:

Error 204 error LNK2005: "private: __thiscall FTFont::FTFont(class FTFontImpl *)" (??0FTFont@@AAE@PAVFTFontImpl@@@Z) already defined in FTFont.obj  buildDir\ftgl.lib(ftgl.dll)
Error 238 error LNK2005: "private: __thiscall FTGlyph::FTGlyph(class FTGlyphImpl *)" (??0FTGlyph@@AAE@PAVFTGlyphImpl@@@Z) already defined in FTGlyph.obj    buildDir\ftgl.lib(ftgl.dll)
Error 249 error LNK2005: "private: __thiscall FTLayout::FTLayout(class FTLayoutImpl *)" (??0FTLayout@@AAE@PAVFTLayoutImpl@@@Z) already defined in FTLayout.obj  buildDir\ftgl.lib(ftgl.dll)
Error 213 error LNK2005: "protected: __thiscall FTFont::FTFont(char const *)" (??0FTFont@@IAE@PBD@Z) already defined in FTFont.obj  buildDir\ftgl.lib(ftgl.dll)

I built the FTGL lib using their provided msvc->vc8 solution (upgraded to vs2010). This created the following files for both debug and release:

ftgl_static.lib
ftgl.lib
ftgl.dll

Placed the libs into my vc lib directory and added them to the Project Settings -> Linker -> Additional Dependencies so that I have the following line:

ftgl.lib
glui32.lib
glut32.lib
glu32.lib
opengl32.lib
freetype.lib
%(AdditionalDependencies)

Don't think it matters since I don't have any unresolved dependencies, but I have the following in my project -> C/C++ -> Additional Include Dirs

$(SolutionDir)..\..\code\lib\freetype2\include\freetype2\config
$(SolutionDir)..\..\code\lib\freetype2\include\freetype2
$(SolutionDir)..\..\code\source
$(SolutionDir)
$(SolutionDir)..\..\code\lib\FTLayout
$(SolutionDir)..\..\code\lib\FTGlyph
$(SolutionDir)..\..\code\lib\FTGL
$(SolutionDir)..\..\code\lib\FTFont
$(SolutionDir)..\..\code\lib
$(SolutionDir)..\..\code\headers
%(AdditionalIncludeDirectories)

Tried playing with ignoring dependencies but didn't get anywhere with that. I have also tried a variety of solutions here and on other sites, including:

• Resolving LNK4098: defaultlib 'MSVCRT' conflicts with
• Google Groups 'FTGL build error'
• How to install FTGL library on windows

Prior to this problem I was seeing the LNK2019 errors described on this gamedev topic . That was solved by adding the lib to the additional dependencies in the project, but introduced the LNK2005 errors.

If it helps, the project builds in OS X; however, the libraries somewhat differ for Windows (dylib in OS X vs lib/dll in Win).

Can anyone help me to resolve these errors?

Answer 1

Make sure you lib are generated with same runtime library option under code generation

• /MD and /MDd is for multi-threaded (debug)
• /MT and /MTd is for multi-threaded DLL (debug)

All projects that have dependency with each other should has same option.

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Also, you might have LIBCMT confliction if import static lib that is built with /MD and /MDd. Add LIBCMT into ignore libraries for linker can avoid this problem.