make

Dependency information

A dependency line lists both targets and components, separated by either one or two colons. A target name can appear on more than one dependency line, but all of those lines must be of the same (single or double-colon) type. For example, if a single colon is used on a dependency line, then only a single set of commands can be associated with that target. If a target appears on more than one single-colon line, only one of those lines can have a command sequence associated with it. The occurrence of targets on multiple single-colon lines is used as a notational convenience for clarifying complex makefiles.

make concatenates all the components following each occurrence of the repeated target into a single dependency list. For example:

   target1 : comp1 comp2
   	commands
   target1 : comp2 comp3

This is identical to:

   target1 : comp1 comp2 comp3
   	commands

A double colon allows the listing of the same target on two or more dependency lines, permitting commands to be associated with each target line. For example:

   target1 target2 :: comp1 comp2
   	commands
   target2 :: comp3
   	commands