What does it mean to 'touch' a target in make?

Question

For example, from the mingw32-make.exe --help option:

-t, --touch                 Touch targets instead of remaking them.

Answer 1

Touching a file means creating it if it doesn't already exist and updating its modification date, so using -t will probably make make think that everything was compiled, but not actually compile everything.

Answer 2

It's not dirty ;)

It just means to update the file modification time, so that next time, it won't consider those files old.

Answer 3

Touching a file means to write to it without writing any data to it.

The file will be created if it doesn't exist and its modification time will be set to now, as if you had written data to it.