How are Ada rep-specs translated directly to C-field specs? (i.e. Ada LSB is nominally C-language MSB)

How are Ada rep-specs translated directly to C-field specs? (i.e. Ada LSB is nominally C-language MSB)

Appropriate C bit-field specifications are include in the C struct definitions. There is a "config" file which can be used to tailor the translator to unusual characteristics of the target C compiler, though the default "config" file works in most cases.