https://gcc.gnu.org/bugzilla/show_bug.cgi?id=8270
--- Comment #57 from Kai Tietz <ktietz at gcc dot gnu.org> --- (In reply to doug mcilroy from comment #56) > (In reply to Kai Tietz from comment #55) > Comment #55 overlooks the Standard's translation phase 1, which replaces an > implementation-defined end-of-line indicator with a new-line character. > GCC's convention of including in the end-of-line indicator any white space > that is preceded by a backslash conforms, though it may be a surprise. Sure, sorry for omitting that. Common understanding of "multibyte" (this term is indeed misleading here) newline characters are in common the combination of '\r' and '\n'. So by interpreting any whitespace + new-line being seen as a single-character is valid, but has indeed semantic differences. > The surprise is perversely out of sympathy with the raison d'etre of the > standard--maximal portability. It is incompatible with the most direct (and > historically prior) implementations, wherein the end-of-line indicator is > simply a new-line character. Agreed, and we should at least consider to provide an option - beside the necessary warning - to not strip whitespaces from right-handside of lines containing a backslash at line's end. Should we use an existing option (like -ansi), or introduce new option for this? > A suitable fix is to warn when white space occurs in an end-of-line > indicator. This will break no code that GCC currently compiles, yet draw > attention to the nonportable construct. Well, in general we are warning, but within comments. For C-style comments there is indeed not much reason to warn, as there is no semantic difference. But for C++-style comments we should, as here indeed a semantic difference can occure for gnu-style end-of-line treating
