https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68065
--- Comment #32 from Alexander Cherepanov <ch3root at openwall dot com> --- Sorry for the late reply. Decided to read DR 260 and got distracted. It so fundamentally undermines the base of classical C that it took me some time to grasp the scale:-) On 2015-11-12 01:51, joseph at codesourcery dot com wrote: >> 4. From the POV of the standard I don't see much difference between VLA >> and ordinary arrays in this question. AFAICT the standard doesn't place >> limits on constructed types of any kind and hence oversized types are >> permitted by the standard. See comment #3 (or pr68107) for a practical > > "permitted by" only in the sense of "the standard does not require > implementations to reject them". It is not intended that the listed > implementation limits are the only limits that there may be, at compile > time or run time. What does the following mean then? C11, 4p5: "A strictly conforming program[...] It [...] shall not exceed any minimum implementation limit." C11, 4p6: "A conforming hosted implementation shall accept any strictly conforming program." >> 3. The same for sizes of objects. There is an environmental limit for >> "bytes in an object" but it's marked as "(in a hosted environment >> only)". So there is no such limit in the standard for a freestanding >> implementation, right? But I doubt that you are supposed to be able to > > No, what's "in a hosted environment only" is the requirement that the > implementation translate and execute some program with a 65535-byte object > (and an instance of the other given limits, simultaneously); freestanding > implementations may have an object size limit smaller than 65535 bytes. > That is, effectively, C99 and above do not support hosted environments > with a 16-bit address space; systems with a 16-bit address space are only > supported for freestanding implementations. I see, thanks for the info.
