For bigger projects they are considered an anti-pattern and should be disabled (-r), because they can cause all kinds of surprises, (actually, using make to begin with is sortof an anti-pattern) . For example, implicit rules may try to compile using Fortran if it finds a file ending with .f, that's just the tip of the iceberg, getting unexpected outputs or missing outputs is another danger. There are also claims that disabling them can give a performance boost.
For bigger projects they are considered an anti-pattern and should be disabled (-r), because they can cause all kinds of surprises, (actually, using make to begin with is sortof an anti-pattern) . For example, implicit rules may try to compile using Fortran if it finds a file ending with .f, that's just the tip of the iceberg, getting unexpected outputs or missing outputs is another danger. There are also claims that disabling them can give a performance boost.