> I've created two libraries (static ones)
> and the second one uses a function from
> the first one.
>
> I normally link them like this
>
> ar r lib1.a lib1.o
> ranlib r lib1.a
>
> ar r lib2.a lib2.o
> ranlib r lib2.a
>
> then I try to link my program like this
>
> gcc -o program program.o -l1 -l2
>
> The linker keeps telling me that it's
> impossible to find the function called
> in the second library which is normally
> present in the first one. Everything starts
> to work when I call this function in program.c.
>
> Does anybody know how to solve this ?
Reverse the order in which the libraries are linked:
gcc -o program program.o -l2 -l1
GNU ld (the linker called by gcc) will link in only what is needed
up until the current point. If program.o doesn't call anything in
lib1, then lib1 will be ignored in your original comand line. The
linker then moves on to lib2, which is needed because program.o
references something in it. If this generates a dependency on a
symbol in lib1, that will go unresolved, because the linker does not
go back and try lib1 again. Each library is linked once, in the order
given on the command line. If you want the linker to try a library
multiple times, you must list it multiple times on the command line,
as in:
gcc -o program program.o -l1 -l2 -l1
This is perfectly legal, and in fact, used all the time by gcc for
its own internal and standard libraries.
------Carl
