In
C programming language terminology, a
translation unit is the ultimate input to a C
compiler from which an
object file is generated. In casual usage it is sometimes referred to as a
compilation unit. A translation unit roughly consists of a
source file after it has been processed by the
C preprocessor, meaning that
header files listed in
#include
directives are literally included, sections of code within
#ifdef
may be included, and macros have been expanded.