unresolved symbols

[thotasri]

when I am porting my project from Vc6 to vc10 i am getting the following linker errors .actully I am using opencv library for this project .Can any body help me to resolve this problem.


------ Build started: Project: Personal_Authenticationsystem1mar11, Configuration: Debug Win32 ------
1>Build started 3/14/2011 10:02:13 AM.
1>InitializeBuildStatus:
1> Touching "Debug\Personal_Authenticationsystem1mar11.unsucce ssfulbuild".
1>ClCompile:
1> All outputs are up-to-date.
1> Image.cpp
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(216): warning C4244: 'initializing' : conversion from 'double' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(266): warning C4244: 'initializing' : conversion from 'double' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(368): warning C4244: 'initializing' : conversion from 'double' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(558): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(562): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(600): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(604): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(647): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(651): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(688): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(692): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(753): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(757): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(807): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(811): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(828): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(832): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(856): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(860): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(878): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(882): warning C4244: '=' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(1122): warning C4244: 'initializing' : conversion from 'double' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(1199): warning C4244: 'initializing' : conversion from 'double' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(1200): warning C4244: 'initializing' : conversion from 'double' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(1240): warning C4244: 'initializing' : conversion from 'double' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(1241): warning C4244: 'initializing' : conversion from 'double' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(1800): warning C4244: '=' : conversion from 'double' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(1882): warning C4244: '=' : conversion from 'double' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(2450): warning C4244: 'initializing' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(2451): warning C4244: 'initializing' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(2467): warning C4244: 'initializing' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(2468): warning C4244: 'initializing' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(2519): warning C4244: 'initializing' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(2520): warning C4244: 'initializing' : conversion from 'float' to 'int', possible loss of data
1>f:\vcprojects\personal_authenticationsystem1mar1 1\image.cpp(1811): warning C4700: uninitialized local variable 'curr_x' used
1>ResourceCompile:
1> All outputs are up-to-date.
1>ManifestResourceCompile:
1> All outputs are up-to-date.
1>Image.obj : error LNK2019: unresolved external symbol _ijlFree@4 referenced in function "public: int __thiscall Image::LoadFromJPGFile(class ATL::CStringT<char,class StrTraitMFC_DLL<char,class ATL::ChTraitsCRT<char> > >)" (?LoadFromJPGFile@Image@@QAEHV?$CStringT@DV?$StrTr aitMFC_DLL@DV?$ChTraitsCRT@D@ATL@@@@@ATL@@@Z)
1>Image.obj : error LNK2019: unresolved external symbol _ijlRead@8 referenced in function "public: int __thiscall Image::LoadFromJPGFile(class ATL::CStringT<char,class StrTraitMFC_DLL<char,class ATL::ChTraitsCRT<char> > >)" (?LoadFromJPGFile@Image@@QAEHV?$CStringT@DV?$StrTr aitMFC_DLL@DV?$ChTraitsCRT@D@ATL@@@@@ATL@@@Z)
1>Image.obj : error LNK2019: unresolved external symbol _ijlInit@4 referenced in function "public: int __thiscall Image::LoadFromJPGFile(class ATL::CStringT<char,class StrTraitMFC_DLL<char,class ATL::ChTraitsCRT<char> > >)" (?LoadFromJPGFile@Image@@QAEHV?$CStringT@DV?$StrTr aitMFC_DLL@DV?$ChTraitsCRT@D@ATL@@@@@ATL@@@Z)
1>Personal_Authenticationsystem1mar11View.obj : error LNK2019: unresolved external symbol _cvLoadImage referenced in function "public: void __thiscall CPersonal_Authenticationsystem1mar11View::OnFileOp en(void)" (?OnFileOpen@CPersonal_Authenticationsystem1mar11V iew@@QAEXXZ)
1>F:\VCPROJECTS\Personal_Authenticationsystem1mar1 1\Debug\Personal_Authenticationsystem1mar11.exe : fatal error LNK1120: 4 unresolved externals
1>
1>Build FAILED.
1>
1>Time Elapsed 00:00:13.83
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

[Banfa]

An unresolved external is a symbol that you have told the compiler exists in one file but that is not defined in any other file.

The reasons you get an unresolved external may be (but are not limited to)

• You have forgotten to include a library in you link
• You have forgotten to include an cpp file in the compile/link (build)
• You have forgotten to implement a function anywhere
• A preprocessor symbol has the wrong value cause a chunk of code to not be compiled
• There is a typo in the name

[thotasri]

Hi Banfa,

Thanks for your response.Ya its true Now I corrected all the linker errors and the system is working fine but again after running 3 times the following build error is coming i am confusing why this? Actually this projetc is working perfectly in VS 6 .After changing the version to vs2010 all these problems are coming.I am using opencv library in this project.

Thanks in advance

Banfa has responded to your question on Bytes.com:

unresolved symbols

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[thotasri]

sorry i forgot to mention error in the reply

fatal error C1083: Cannot open precompiled header file: '.\Debug\WebCamRead.pch': No such file or directory
1>

[weaknessforcats]

You got his error by not having precompiled header files.

I suspect you created a Win32 console application but failed to click on "Application Settings" where you can specify that you are not using precompiled headers.

Just go to your project properties and for the "Precompiled header" property just specify "not using precompiled headers". The C1083 will now go away