Hello all,

GCC error/warning messages often provide a lot of extra information, which
is great.
It is done on a multiline way, like in:

foo.h:123:22: <context>
... etc
bar.h:234:12: error: <some error>
qwr.h:456:8: <additional context information / possible diagnostics>
.. etc

Nevertheless this has some drawbacks:

- Parallel compilation can mess up mixin lines from sep compilations
- Often one may want to reorder or deduplicate or archive errors, but
associated context lines are not attached to the main error line

Is there a compile option to ask GCC to emit some uuid with every
errors/context lines, so that an automated system may group them and manage
them at once? something like this:

foo.h:123:22:uuid1: <context>
... etc
bar.h:234:12:uuid1: error: <some error>
qwr.h:456:8:uuid1: <additional context information / possible diagnostics>
.. etc

Seems quite an easy feature to support, if it does not exist already.

Regards.