Ralf Wildenhues - Re: PATCH RFC: -Wstrict-overflow, take 2 (original) (raw)

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• From: Ralf Wildenhues
• To: Ian Lance Taylor
• Cc: gcc-patches at gcc dot gnu dot org
• Date: Sat, 10 Feb 2007 13:21:47 +0100
• Subject: Re: PATCH RFC: -Wstrict-overflow, take 2
• References: <m3hctwgi1d.fsf@localhost.localdomain>

Hello Ian, all, * Ian Lance Taylor wrote on Fri, Feb 09, 2007 at 03:51:26AM CET:

Here is a new version of my -Wstrict-overflow patch. This incorporates all the comments made on the first version.

A small nit, with "pedantic user" glasses on: in the documentation
addition, it isn't totally clear that each higher warning level adds
warnings, as opposed to, say, simply outputs a different set of
warnings, unrelated to the previous lower level. In the description
of the patch, the word "additionally" makes this clear:

-Wstrict-overflow=2 additionally warns about cases where a conditional expression is folded to a constant. A typical example would be (abs (x) >= 0), which will be folded to 1 (this optimization will yield an unexpected result if x == INT_MIN).

[...] vs.

+@item -Wstrict-overflow=2 +Warn about other cases where a comparison is simplified to a constant. +For example: @code{abs (x) >= 0}. This can only be simplified when +@option{-fstrict-overflow} is in effect, because @code{abs (INT_MIN)} +overflows to @code{INT_MIN}, which is less than zero.

Either "Also, ", "Additionally, ", or alternatively change the intro:

+actually a problem. To help focus on important issues, several +warning levels are defined.

to something like this:
... several warning levels with increasing amount of warning cases
are defined. Cheers,
Ralf

• References:
  • PATCH RFC: -Wstrict-overflow, take 2
    * From: Ian Lance Taylor