"Seongbae Park" <[EMAIL PROTECTED]> writes: | On 30 Dec 2006 03:20:11 +0100, Gabriel Dos Reis | <[EMAIL PROTECTED]> wrote: | ... | > The C standard, in effect, has an appendix (Annex H) that was not | > there in the C89 edition, and that talks about the very specific issue | > at hand | > | > H.2.2 Integer types | > | > [#1] The signed C integer types int, long int, long long | > int, and the corresponding unsigned types are compatible | > with LIA-1. If an implementation adds support for the LIA-1 | > exceptional values ``integer_overflow'' and ``undefined'', | > then those types are LIA-1 conformant types. C's unsigned | > integer types are ``modulo'' in the LIA-1 sense in that | > overflows or out-of-bounds results silently wrap. An | > implementation that defines signed integer types as also | > being modulo need not detect integer overflow, in which | > case, only integer divide-by-zero need be detected. | | which clearly says LIA-1 isn't a requirement - notice "if" in the | second setence.
I never said it was a requirement, right? | H.1 makes it clear that the entire Annex H doesn't add any extra rule | to the language but merely describes what C is in regard to LIA-1. | H.2 doubly makes it clear that C as it defined isn't LIA-1 | - again, notice "if" in H.2p1. | The second sentence of H.3p1 confirms this again: | | C's operations are compatible with LIA−1 in that C | allows an implementation to cause a notification to occur | when any arithmetic operation | returns an exceptional value as defined in LIA−1 clause 5. | | i.e. "compatible" means C's definition doesn't prevent | a LIA-1 conformant implementation. Right. | In other words, all LIA-1 comformant compiler is conformant to C99 | in terms of arithmetic and types. Right. | However, not all C99 conformant compiler aren't LIA-1 conformant. Right. | C isn't conformant to LIA-1 but merely compatible, | exactly because of the undefined aspect. I don't think it is accurate to say that C isn't conformant yp LIA-1, since its specification does make room for LIA-1 conformance, indicating how that can be made. A point made at the very begining of this thread. -- Gaby
