1. Some of my macros are written from scratch (they use the Autoconf
macros, of
course, including the internal ones like _AC_COMPILER_EXEEXT_CROSS). This
case
looks like the easiest one to me and I guess, I can add my own license
(preferably, BSD-3c) and copyright header there.
2. Some of the macros are refactored versions of the Autoconf macros (NOT
the
Autoconf Archive macros). For example, I copied AC_FC_LINE_LENGTH from
fortran.m4 to a separate file, renamed the macro to ACX_FC_LINE_LENGTH,
fixed a
couple of issues and refactored it. As far as I understand, I must copy the
whole license header from fortran.m4 to my file. There are three things
that I
am not sure about:
a) may I omit the first two lines saying that "This file is part of
Autoconf..." because they look a bit misleading in this context?
b) may I add an extra copyright line?
c) do I have to provide any extra information in the file?