Fwd: Updating copyright dates automatically

[Joseph S. Myers]

On Wed, 2 Jan 2013, Jeff Law wrote:

> I've always found lazily updating the copyright years to be error prone.  If
> we could just update all of them now, which is OK according to the FSF
> guidelines we could avoid one class of problems.

I suspect dealing with generated files will be more complicated for GCC 
than for glibc.  There are more of them, and many of them are 
architecture-specific with update rules in architecture makefile 
fragments, so a simple "make" for one architecture won't regenerate them 
all as it does for glibc.  Some may require unusual tools, or special 
versions of tools, or not have makefile rules at all (e.g. the various ARM 
files generated using O'Caml).  Some may not be listed in 
contrib/gcc_update either, further complicating identifying them all, 
although that's certainly a useful place to start getting information 
about generated files in the source tree.  And it's often the case for 
generated files in GCC that the generator has both its own copyright 
notice at the top of the file, and a later one that gets put in the 
generated file, so both need updating before regenerating the generated 
file (but update-copyright only updates one copyright notice per file).

It may make sense to start automation with a limited set of files, under 
the gcc/ directory only and excluding both generated files and their 
sources, before gradually extending what's covered by automation for 
updating copyright notices.

Other ways of looking for generated files, apart from targets in makefiles 
and makefile fragments that update files in srcdir, and apart from the 
lists in gcc_update, include looking for characteristic comments such as 
"automatically generated", "Generated automatically", "do not edit 
manually" and "-*- buffer-read-only: t -*-" that various generators 
output.  (When such things are found, appropriate makefile rules and 
gcc_update entries could then be added to make future regenerations 
easier.)

-- 
Joseph S. Myers
joseph@codesourcery.com