Re: differential code coverage

Hi,

On 2023-04-04 09:03:45 -0700, Andres Freund wrote:
> For quite a while I'd been wishing to see *differential* code coverage, to see
> what changed in code coverage between two major releases. Unfortunately lcov
> didn't provide that. A few months ago a PR for it has been merged into lcov
> ([1]). There hasn't yet been a release though. And the feature definitely has
> some rough edges, still.
>
> I'm planning to generate the 15->16 differential code coverage, once the
> feature freeze has been reached.
>
> Another nice thing provided by the in-development lcov is hierarchical
> output. I find that to be much easier to navigate than the current flat
> output, as e.g. used on coverage.postgresql.org.

I've generated the output for 15 vs HEAD, now that we're past feature freeze.

Simpler version:
https://anarazel.de/postgres/cov/15-vs-HEAD-01/

Version that tries to date the source lines using information from git:
https://anarazel.de/postgres/cov/15-vs-HEAD-02/

The various abbreviations are explained (somewhat) if you hover over them.

There's a few interesting bit of new code not covered by teests, that should
easily be coverable:

https://anarazel.de/postgres/cov/15-vs-HEAD-01/src/bin/pg_dump/pg_dumpall.c.gcov.html#1014

https://anarazel.de/postgres/cov/15-vs-HEAD-01/src/backend/utils/adt/array_userfuncs.c.gcov.html#675
https://anarazel.de/postgres/cov/15-vs-HEAD-01/src/backend/utils/adt/array_userfuncs.c.gcov.html#921

https://anarazel.de/postgres/cov/15-vs-HEAD-01/src/backend/utils/adt/pg_locale.c.gcov.html#1964
https://anarazel.de/postgres/cov/15-vs-HEAD-01/src/backend/utils/adt/pg_locale.c.gcov.html#2219

https://anarazel.de/postgres/cov/15-vs-HEAD-01/src/backend/parser/parse_expr.c.gcov.html#3108
https://anarazel.de/postgres/cov/15-vs-HEAD-01/src/backend/nodes/nodeFuncs.c.gcov.html#1480
https://anarazel.de/postgres/cov/15-vs-HEAD-01/src/backend/nodes/nodeFuncs.c.gcov.html#1652

https://anarazel.de/postgres/cov/15-vs-HEAD-01/src/backend/optimizer/util/plancat.c.gcov.html#348

https://anarazel.de/postgres/cov/15-vs-HEAD-01/contrib/postgres_fdw/connection.c.gcov.html#1316
https://anarazel.de/postgres/cov/15-vs-HEAD-01/contrib/postgres_fdw/deparse.c.gcov.html#399

Greetings,

Andres Freund