Re: run pgindent on a regular basis / scripted manner

On Fri, Jan 20, 2023 at 10:43:50AM +0100, Jelte Fennema wrote:
> Side-question: What's the reason why pgindent is used instead of some
> more "modern" code formatter that doesn't require keeping
> typedefs.list up to date for good looking output? (e.g. uncrustify or
> clang-format) Because that would also allow for easy editor
> integration.

One reason the typedef list is required is a quirk of the C syntax.
Most languages have a lexer/scanner, which tokenizes, and a parser,
which parses. The communication is usually one-way, lexer to parser.
For C, typedefs require the parser to feed new typedefs back into the
lexer:

http://calculist.blogspot.com/2009/02/c-typedef-parsing-problem.html

BSD indent doesn't have that feedback mechanism, probably because it
doesn't fully parse the C file. Therefore, we have to supply typedefs
manually, and for Postgres we pull them from debug-enabled binaries in
our buildfarm. The problem with that is you often import typedefs from
system headers, and the typedefs apply to all C files, not just the ones
were the typdefs are visible.

I don't see uncrustify or clang-format supporting typedef lists so maybe
they implemented this feedback loop. It would be good to see if we can
get either of these tools to match our formatting.

--
Bruce Momjian <bruce(at)momjian(dot)us> https://momjian.us
EDB https://enterprisedb.com

Embrace your flaws. They make you human, rather than perfect,
which you will never be.