Stored procedure version control

Elsewhere, somebody was asking how people implemented version control
for stored procedures on (MS) SQL Server.

The consensus was that this is probably best managed by using scripts or
command files to generate stored procedures etc., but does anybody have
any comment on that from the POV of PostgreSQL?

--
Mark Morgan Lloyd
markMLl .AT. telemetry.co .DOT. uk

[Opinions above are the author's, not those of his employers or colleagues]