An object file can refer to external symbols that are, for example, functions or variables. The linker attempts to resolve these references by matching them to definitions found in other object files and libraries. The linker recognizes a collection of ELF files stored in an ar format file as a library. The contents of each ELF file forms a single member in the library.

If you use --sysv to generate an SVr4 formatted ELF executable file, the linker treats a shared object as a library. Similarly, a shared object or DLL is treated as a library when you are generating a BPABI-compatible executable file. However, a shared object or DLL differs from an archive in that:

The rest of this chapter describes archives.