Impact of bugs on different versions.

[Jonathan Wakely]

On 21 September 2017 at 12:56, Vicent Brocal wrote:
> Hello everyone,
>
> I am trying to figure out which are the problems affecting a specific
> version of GCC (4.4.2) from the information in the bug tracker
> (https://gcc.gnu.org/bugzilla/).
>
> So far I have been able to get a list of the bugs restricted to
> standalone C components (c, inline-asm, ipa, preprocessor, regression,
> rtl-optimization, target, tree-optimization) and filtering "known to
> fail" field to 4.4.2.
>
> Does that cover the case when for example a bug was detected for 4.4.5
> that also impacts 4.4.2?

No.

> How exhaustively previous versions in the same
> series (e.g 4.4) are checked when a problem is discovered in a newer
> version (e.g 4.4.5)?

Not at all exhaustively. Even if someone tests it and confirms it's
present in that version, typically it wouldn't get listed in the Known
to fail field.

In general if a bug affects 4.4.5 and is not marked as a Regression
(in the bug summary) then it is safe to assume it also affected all
earlier 4.4.x releases

That field isn't even always populated (it's only required for
regressions). You also need to look at the Version field.

A bug could have been detected in 4.4.1 and not fixed until 4.4.3, in
which case it would be present in 4.4.2 but that wouldn't be in the
Known to fail field, or the Version field.

Or a bug could have been detected in 4.5.0 and fixed for 4.5.1, but
also present in older versions too, including 4.4.2. But you wouldn't
find any 4.4.x number in any field.

You're going to need to do a **lot** more work than simply inspecting
the Known to fail field, or any simple combination of fields.