RFR: 8275745: Reproducible copyright headers

[Magnus Ihse Bursie]

On Sat, 28 Nov 2020 23:14:35 GMT, Emmanuel Bourg <duke at openjdk.java.net> wrote:

> The copyright headers are generated at build time, and the year inserted in the template depends on the current date. This means the headers are not reproducible if the project is built a year later. The year in the headers could be derived from the SOURCE_DATE_EPOCH environment variable to make the build reproducible (this variable is already used in other parts of the build).

I see your point. I'd prefer, though, to rather make `--with-copyright-year` pick up `SOURCE_DATE_EPOCH`, if present, and to use the copyright year to propagate to the gensrc files. If you're okay with it, I can help you modify this patch to do that.

-------------

PR: https://git.openjdk.java.net/jdk/pull/1498