Re: [RFC] warning: initialization discards qualifiers from pointer target type

[Mike Stump <mrs at apple dot com>]

On Apr 18, 2005, at 6:29 PM, James E Wilson wrote:
> This seems rather unlikely to be an accident.

I agree, I'm sure it was due to bad system header files, only some of  
which had const and others didn't.  By ignoring the issue in the  
compiler, the compiler works on such (broken) systems.  The usual  
case I think was a system that had a compiler that did const, but the  
OS hadn't added it yet, but people built software that made use of  
const, and presto, it wouldn't compile.  In the C++ world, we did the  
same thing (we used warning as I recall) for a long time, but that  
was due to bugs in the compiler, where const wasn't propagated around  
correctly internally, so, instead of pestering the user with error  
messages they could not fix, we just made it a warning by default.   
The idea was eventually we'd weed them all out and make it an error;  
today, it is an error.

> I notice that these are pedwarns, not a warning as in the -Wcast- 
> qual case, which means that the ISO C standard requires a  
> diagnostic here. For this reason, it may not be wise to add an  
> option to disable the warnings.  You may lose portability to other  
> compilers.

If we had a framework for disabling warnings....  it probably would  
just fit into it.  :-)