Relinking an existing executable file

The linker accepts executable files as input, so you can link an existing executable file with updated object files.

You cannot, however, relink executable files that were previously linked using the -qipa option.

If you have a program consisting of several source files and only make localized changes to some of the source files, you do not necessarily have to compile each file again. Instead, you can include the executable file as the last input file when compiling the changed files:
  xlc -omansion front_door.c entry_hall.c parlor.c sitting_room.c \
    master_bath.c kitchen.c dining_room.c pantry.c utility_room.c

  vi kitchen.c # Fix problem in OVEN function

  xlc -o newmansion kitchen.c mansion
Limiting the number of files to compile and link the second time reduces the compile time, disk activity, and memory use.
Note: You should avoid this type of linking unless you are experienced with linking. If done incorrectly, it can result in interface errors and other problems. If you do encounter problems, compiling with the -qextchk compiler option can help you diagnose problems with linking.