On 2017-06-01 13:42:10 +0200, Toebs Douglass wrote: > So, I may be completely wrong, but I can see basically two cases where > this header file name conflict occurs; > > 1. by accident In this case, a warning/error is expected. > 2. intentionally (perhaps emulating the later standard header files, to > make moving up to a later version easier) In this case, there should be a way to disable the corresponding check. But note that for (2), I would first expect that programs are written to support both C90 and a later standard, in which case a conflict should not occur. One could write something like: #if ... #include <stdint.h> #else #include "our-stdint.h" #endif This is more or less what MPFR does with its mpfr-intmax.h, but the #else case is never tested because <stdint.h> is always detected as being available, even with -std=c90 -pedantic-errors. > I expect there is nothing anywhere which states using header names which > will be part of a *later* standard is *wrong*, in which case this cannot > be an error. Just like there is nothing anywhere which states using string lengths over the C90 implementation limit (which is ridiculously low) is wrong. But such strings are rejected by -std=c90 -pedantic-errors as expected. > I can also see a use case where this behaviour is *normal* and is > helpful to the user. > > However, I can certainly imagine users wanting to be informed of the > situation if they did *not* intend it - they did not intend to use a > name which conflicts with later versions of the standard - and if the > user is compiling with pedantic, it feels like he is specifically asking > to be informed of such things. > > Can we perhaps say that there should normally be no warning or error, > since we can see there *is* a normal use case where this behaviour is > intended as is useful, but that in pedantic mode, there is at least a > warning here, since we are specifying an earlier version of C, but using > a header file name which will conflict with a later version of C. Yes, this is exactly what I suggested. -- Vincent Lefèvre <vincent@xxxxxxxxxx> - Web: <https://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
