NAME

Signature::exact_match -- a signature class that requires that dependencies have exactly the same signature they did on the last build

USAGE

This is the default signature class. You don't have to do anything to use it unless you override it from the command line. You can specify it explicitly in the Makefile using

   target : dependencies
	  : signature exact_match
	$(commands_to_build)

DESCRIPTION

This class forces a recompilation if any of the following are different from the last time this particular rule was executed:

• The build command or the directory from which it is executed.

• The architecture this is running on (e.g., i386, sparc, alpha, etc.).

• The signatures of each dependency.

Returns undef if no build is necessary, or a true value if a build is necessary.