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Re: Should a disabled warning be allowed to be promoted to an error(Bugzilla PR 70275)?
- From: Jeff Law <law at redhat dot com>
- To: Martin Sebor <msebor at gmail dot com>, Segher Boessenkool <segher at kernel dot crashing dot org>
- Cc: Florian Weimer <fw at deneb dot enyo dot de>, kevin-tucker at cox dot net, gcc at gcc dot gnu dot org, dodji at redhat dot com, dmalcolm at redhat dot com
- Date: Fri, 1 Apr 2016 08:35:52 -0600
- Subject: Re: Should a disabled warning be allowed to be promoted to an error(Bugzilla PR 70275)?
- Authentication-results: sourceware.org; auth=none
- References: <20160328142309 dot CKMHR dot 556080 dot imail at eastrmwml106> <87r3eul6ki dot fsf at mid dot deneb dot enyo dot de> <56F9B112 dot 6080704 at gmail dot com> <20160331163036 dot GA20004 at gate dot crashing dot org> <56FDED6F dot 7030105 at gmail dot com>
On 03/31/2016 09:39 PM, Martin Sebor wrote:
On 03/31/2016 10:30 AM, Segher Boessenkool wrote:
On Mon, Mar 28, 2016 at 04:32:50PM -0600, Martin Sebor wrote:
On 03/28/2016 01:56 PM, Florian Weimer wrote:
In Bugzilla PR # 70275, Manuel López-Ibáñez reports that even though
he provides the "-Werror=return-type" option, the compiler doesn't
flag the warning/error about a control reaching the end of a non-void
function, due to the presence of the "-w" option. He points out that
clang++ wtill flags the promoted warning even though warnings are
I think -w is ordered with respect to the other warning obtions, and
-w inhibits previously requested warnings, and future -W flags may
enable other warnings. With this in mind, I agree that the current
GCC behavior is consistent and probably not a bug.
The general rule of thumb documented in the manual is that more
specific options take precedence over more general ones, regardless
of where they appear on the command line:
Currently, -w is a nice easy quick way of shutting up all warnings
whenever they are getting in the way. Let's keep it that way.
I agree that having a knob to suppress all warnings can be useful.
At the same time, having the ability to do what PR 70275 asks for
(i.e., suppress only warnings that have not be been explicitly
enabled or elevated to errors) can be handy as well. If it's
preferable to keep -w unchanged, providing a new option to do it
might be worth considering.
Given the long standing behavior of -w, I think it should remain unchanged.