Linker Error when attempting to use binary external library - visual-c++

Question

I am new to C++, having recently taken a class to introduce me to the language, so I understand the basics of the syntax, but there was no discussion of how to use external libraries and connect them to our code.
I am trying to use the CLP COIN library for solving linear programs from...
http://www.coin-or.org/Clp/userguide/clpuserguide.html#id4766717
From what I read there, it suggested to use the precompiled binary libraries rather than download the source, since I am on Windows 7 platform, as they suggested recompiling on Windows can sometimes introduce problems.
I am simply trying to get the equivalent of Hello World working. Here is the sample code they provided to test with...
* Copyright (C) 2004, International Business Machines Corporation
and others. All Rights Reserved.
This sample program is designed to illustrate programming
techniques using CoinLP, has not been thoroughly tested
and comes without any warranty whatsoever.
You may copy, modify and distribute this sample program without
any restrictions whatsoever and without any payment to anyone.
*/
/* This shows how to provide a simple picture of a matrix.
The default matrix will print Hello World
*/
#include "ClpSimplex.hpp"
int main (int argc, const char *argv[])
{
ClpSimplex model;
int status;
// Keep names
if (argc<2) {
status=model.readMps("hello.mps",true);
} else {
status=model.readMps(argv[1],true);
}
if (status)
exit(10);
int numberColumns = model.numberColumns();
int numberRows = model.numberRows();
if (numberColumns>80||numberRows>80) {
printf("model too large\n");
exit(11);
}
printf("This prints x wherever a non-zero elemnt exists in matrix\n\n\n");
char x[81];
int iRow;
// get row copy
CoinPackedMatrix rowCopy = *model.matrix();
rowCopy.reverseOrdering();
const int * column = rowCopy.getIndices();
const int * rowLength = rowCopy.getVectorLengths();
const CoinBigIndex * rowStart = rowCopy.getVectorStarts();
x[numberColumns]='\0';
for (iRow=0;iRow<numberRows;iRow++) {
memset(x,' ',numberColumns);
for (int k=rowStart[iRow];k<rowStart[iRow]+rowLength[iRow];k++) {
int iColumn = column[k];
x[iColumn]='x';
}
printf("%s\n",x);
}
printf("\n\n");
return 0;
}
I have associated the Include and Lib directories with my project in Visual Studio, but when I attempt to build, get a number of linker errors such as:
Simplex(void)" (??1ClpSimplex##QAE#XZ) referenced in function _main
1>hello.obj : error LNK2019: unresolved external symbol "public: virtual __thiscall CoinPackedMatrix::~CoinPackedMatrix(void)" (??1CoinPackedMatrix##UAE#XZ) referenced in function _main
1>hello.obj : error LNK2019: unresolved external symbol "public: void __thiscall CoinPackedMatrix::reverseOrdering(void)" (?reverseOrdering#CoinPackedMatrix##QAEXXZ) referenced in function _main
1>hello.obj : error LNK2019: unresolved external symbol "public: __thiscall CoinPackedMatrix::CoinPackedMatrix(class CoinPackedMatrix const &)" (??0CoinPackedMatrix##QAE#ABV0##Z) referenced in function _main
1>hello.obj : error LNK2019: unresolved external symbol "public: int __thiscall ClpSimplex::readMps(char const *,bool,bool)" (?readMps#ClpSimplex##QAEHPBD_N1#Z) referenced in function _main
1>hello.obj : error LNK2019: unresolved external symbol "public: __thiscall ClpSimplex::ClpSimplex(bool)" (??0ClpSimplex##QAE#_N#Z) referenced in function _main
As a newbie, I am clueless as to how to approach resolving this issue, since my course only covered debugging associated with code syntax, not linker issues.
Any tips or links to other threads would be of great help. I have been Googling all day, but am at a loss...

Answer 1

I'm not sure exactly what you did to associate the Lib directories with the project, but you'll need to make sure that these are done (the first is often overlooked):
You need to add the library filename to the Project's "Linker/Input/Additional Dependencies" property.
You might also need to place the location of the library in the Project's "Linker/General/Additional Library Directories" property - depending on if you give the proper path or just the filename ion the above property. This is probably what you already did.
Update:
In the dumpbin output you posted, you'll see the following entry:
4C3 0000AE4A SECT98 notype () External | ?readMps#ClpSimplex##QEAAHPEBD_N 1#Z (public: int __cdecl ClpSimplex::readMps(char const *,bool,bool))
In the error message, you'll see this:
1>hello.obj : error LNK2019: unresolved external symbol "public: int __thiscall ClpSimplex::readMps(char const *,bool,bool)" (?readMps#ClpSimplex##QAEHPBD_N1#Z) referenced in function _main
Compare the de-mangled names from the two messages:
public: int __cdecl ClpSimplex::readMps(char const *,bool,bool) // what's in the .lib
public: int __thiscall ClpSimplex::readMps(char const *,bool,bool) // what hello.obj is asking for
You'll see that the two calling conventions are different. Looking on the coin-or.org website, it looks like the library was built with VC 2005. For Microsoft compilers, the libraries cannot always be used with different compiler versions. I suggest that you use VC 2005 if you want to use this pre-built library (you should still be able to get the free Express version here: http://go.microsoft.com/fwlink/?linkid=57034).
FWIW, I tried compiling the example with several MS compilers and got the following results (build only - the program complains about some file being missing when I try to run it:
worked: VC 2005 and VC 2008
failed: VC 6 and VC2010