Configuring a library to be included with C++ test - c++

Question

I would like to utilize the UnitTest++ library in a testing file. However, I am having some difficulty getting the library to be included at compile time. So here is my current directory structure:
tests/
UnitTests++/
libUnitTest++.a
src/
UnitTests++.h
unit/
test.cpp
I have just used the UnitTest++ getting started guide to just get the library setup. Here is test.cpp:
// test.cpp
#include <UnitTest++.h>
TEST(FailSpectacularly)
{
CHECK(false);
}
int main()
{
return UnitTest::RunAllTests();
}
And I am currently trying to compile with:
gcc -lUnitTest++ -L../UnitTest++/ -I../UnitTest++/src/ test.cpp
I am currently getting a bunch output with ld: symbol(s) not found at the end. So how would I be able to get the UnitTest++ library properly included when this program is compiled? I am on a Mac and I'd also like for there to be an easy way for people on a Linux machine to run these same tests.
Whew, I hope this provides enough information, if not please let me know.

Answer 1

I was able to build it in the following manner
gcc -L../UnitTest++/ -I../UnitTest++/src/ test.cpp -lUnitTest++ -lstdc++
or
g++ -L../UnitTest++/ -I../UnitTest++/src/ test.cpp -lUnitTest++
that links to libstdc++ automatically.
GCC documentation says:
-llibrary
-l library
Search the library named library when linking. (The second alternative with the library as a separate argument is only for POSIX compliance and is not recommended.)
It makes a difference where in the command you write this option; the linker searches and processes libraries and object files in the order they are specified.
Thus, foo.o -lz bar.o' searches libraryz' after file foo.o but before bar.o. If bar.o refers to functions in `z', those functions may not be loaded.
I guess that's why the library symbols are not found when you first specify -lUnitTest++ and then test.cpp

Answer 2

Compile test.cpp to get test.o
and use
g++ test.o libUnitTest++.a -o ./exectest
to get the ./exectest executable
libUnitTest++.a is just an archive of all the object files of UnitTest++. You just need to link all the object files (your test object file + libUnitTest++.a)
Try editing the makefile that came with unittest++ and make it suitable for your case

Answer 3

The message ld: symbol(s) not found means you haven't compiled the library. So you need to go in the UnitTest++ folder, compile and install it.
I've never worked on a MAC, but in linux, libraries are usually compiled and installed with:
./configure
make
make install
In the UnitTest++ link you posted, you should simply:
make install
Then you will have the UnitTest++.so library in the libraries folder of your OS. Now the library can be linked with your program with the -lUnitTest++ command.

Answer 4

Usually you have to put -Lsomething before the -lsomething that requires it.