This is the mail archive of the gcc-patches@gcc.gnu.org mailing list for the GCC project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: [RFA] [PATCH] Add a warning for invalid function casts


On Thu, 5 Oct 2017, Bernd Edlinger wrote:

> But why is int(*)(int) compatible to (int)(*)() but not
> to int(*)(int,...) ?

I think it's a matter of what function types were possible in K&R C.  
<stdarg.h> variadic types weren't (there was an older <varargs.h>), and 
neither were types with arguments of type float or narrower-than-int 
integers (because those always got promoted to a wider type when passed as 
function arguments to an unprototyped function).  And those types that 
were impossible in K&R C always require function prototypes.  (The 
possibility of function types without a prototype is a legacy feature.  
There was some suggestion of removing it for C11, but no-one ever produced 
a paper for WG14 proposing the actual wording changes that would have been 
needed.)

-- 
Joseph S. Myers
joseph@codesourcery.com


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]