On 04/05/2012 12:30 PM, Vincent Lefevre wrote: > On 2012-04-05 11:55:45 +0100, Andrew Haley wrote: >> On 04/05/2012 11:50 AM, Vincent Lefevre wrote: >>> On 2012-04-04 20:01:27 +0100, Andrew Haley wrote: >>>> On 04/04/2012 07:11 PM, Gabriel Dos Reis wrote: >>>>> Really? Such as what? >>>> >>>> Such as "I wrote a perfectly legal C program, and gcc spewed out >>>> a ton of messages." >>> >>> What's a "legal C program"? >> >> It's generally used to mean one that is fully defined by the >> specifications in effect, often some combination of POSIX and ISO C, >> with perhaps some vendor extensions. Why do you ask? > > Because: What if the specifications in effect say (as some vendor > extension) that some construct will generate some warning?
Interesting. I had not considered that, but I have never seen such a specification. Usually warnings are for things that are permitted by a specification, but not "good" in some way. That's why warnings are usually optional, AFAIK; the program is well-defined, but has some properties that are, in the opinion of the compiler writer, undesirable. > Note that warnings in general are not forbidden by ISO C, so that > there is nothing wrong as far as ISO C is concerned. No, but ISO C only talks about diagnostics anyway: there is no real distinction between warnings and errors. Andrew.
