library that links to libraries

How does it link to the other libraries it uses?

I created a static library that itself links to other libraries that it uses.You don't mention, if you link statically or dynamically to the other libraries. If the latter, this obviously won't work. If your library is itself dynamic and you link in static libraries, you might run into trouble, depending how the static libraries are compiled (i.e. if they contain position independent code or not). If your library is static and you link in the other libraries statically this should work as you expect.

-L is the directory in which the libraries are to be found. -l is used to link in the libraries themselves.

Note that when you use -l you omit the "lib" at the start of the name and the ".a" or ".so" at the end, and the default I think if both exist is to link in the .so

I thought (I could be wrong) that you cannot link static libraries to static libraries. All the linker does is confirm that it can find all the proper symbols, but it doesn't actually link the libraries together into one big library. I think that you still need to add all the static libs to your executable link line.

Viggy

I thought (I could be wrong) that you cannot link static libraries to static libraries. All the linker does is confirm that it can find all the proper symbols, but it doesn't actually link the libraries together into one big library.OK, true.

I thought I had done something like that years back, but now I checked and found it was a bit hacky.

Here is how it went:

$ # compile a.c and b.c
$ gcc -c a.c
$ gcc -c b.c
$ # Create an static library from a.o and b.o
$ ar rcs libab.a a.o b.o
$ # Cleanup
$ rm a.o b.o
$ # List the contents of the library
$ nm libab.a

a.o:
00000000 T a

b.o:
00000000 T b
$ # compile c.c
$ gcc -c c.c
$ # Create a static library from c.o and the archives in libab.a
$ ar rcs libabc.a c.o `ar xv libab.a | sed -e"s/x -//"`
$ # List the contents of the new library
$ nm libabc.a

c.o:
00000000 T c

a.o:
00000000 T a

b.o:
00000000 T b

That's it. I remember now. One of the reasons for not creating one big library from a bunch of little static libraries is this. What if you have two libraries that link in the same smaller library? Then, what if you link those two libraries to an executable? Which code should the linker use for the common library?

Kinda similar to the C++ diamond inheritance issue.

Viggy

Well, you do need to export them from the DLL. Either using a DEF file, or using '__declspec(dllexport)'. Well, on Windows anyway (in *NIX, everything is "exported").

Viggy