How to build a static library using another one?

How to build a static library using another one?

[Long Li]

Hi, Guys,

I am a newbie on making library in C & C++. I have
some c++ souce code files(a.cpp, b.cpp) and a C++
library(libutil.a) at hand. The c++ source code
files(a.cpp, b.cpp) use the functions of library
libtuil.a. I would like to build a single library
using them. This is what I tried:

I first compiled the source code files. Then I use

ar rc libcpp.a a.o b.o libutil.a
ranlib libcpp.a

It works fine. However, later when I used this library
in my other souce files, I got some compile error. It
seems the compiler found some undefined symbols in a.o
and b.o, those symbols happen to be the functions in
libtutil.a. 

Could you tell me how to make it work?

Thanks a lot!


Long 

__________________________________________________
Do You Yahoo!?
Yahoo! Health - Feel better, live better
http://health.yahoo.com

Re: How to build a static library using another one?

[Oscar Fuentes]

Long Li <long21st@yahoo.com> writes:

> Hi, Guys,
> 
> I am a newbie on making library in C & C++. I have
> some c++ souce code files(a.cpp, b.cpp) and a C++
> library(libutil.a) at hand. The c++ source code
> files(a.cpp, b.cpp) use the functions of library
> libtuil.a. I would like to build a single library
> using them. This is what I tried:
> 
> I first compiled the source code files. Then I use
> 
> ar rc libcpp.a a.o b.o libutil.a
> ranlib libcpp.a
> 
> It works fine. However, later when I used this library
> in my other souce files, I got some compile error. It
> seems the compiler found some undefined symbols in a.o
> and b.o, those symbols happen to be the functions in
> libtutil.a. 
> 
> Could you tell me how to make it work?

Try this:

move libutil.a, a.o and b.o to an empty directory.

On that directory do:

ar x libutil.a

ar rc libcpp.a *.o
ranlib libcpp.a

See if libcpp.a works for you. If it doesn't, try creating a dummy
executable that uses a.o, b.o and libutil.a. If it still complains
about undefined symbols, maybe the problem is in your object files,
not on the procedure for building the library.

-- 
Oscar