Re: WIP pgindent replacement

From: Bruce Momjian <bruce(at)momjian(dot)us>
To: Andrew Dunstan <andrew(at)dunslane(dot)net>
Cc: David Christensen <david(at)endpoint(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: WIP pgindent replacement
Date: 2011-06-22 14:16:28
Message-ID: 201106221416.p5MEGSu23611@momjian.us
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Andrew Dunstan wrote:
> >> Further research shows that C89 explicitly dropped support for the old
> >> K&R "=-" operator, so we probably *should* remove this in case it
> >> introduces an unintended bug.
> > Well, the point is if someone does use that, it isn't going to generate
> > a pgindent error, but rather produce incorrect C code because =- is
> > going to be changed. FYI, my gcc 2.95.3 allows =- and does work as
> > intended.
> >
>
> As intended by whom? If the effect of "x=4; x =- 1;" is to subtract 1
> from x then that's simply wrong by C89. It should assign -1 to x. The
> "=-" must be parsed as two operators in C89, assignment and unary minus.
> pgindent should not under any circumstances change the semantics of the
> program being indented, and that's what this transformation does for
> compilers conforming to the standard we explicitly follow.
>
> What happens when your ancient gcc is told to apply the ansi standard?

I see now that my test wasn't complete. You are right it assigns -1 so
we can remove this from pgupgrade.

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

+ It's impossible for everything to be true. +

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