* Vincent Lefevre: > On 2017-05-15 15:25:01 +0200, Mason wrote: >> Isn't it UB to (re)define standard functions? > > Hmm... Actually yes, if there is an external linkage (7.1.3). So, > I would expect a warning by the compiler, as this should be easily > detectable. For fma(), this is also an incompatibility introduced > by C99 (AFAIK, fma wasn't reserved in C89). C-related standards retroactively claim such obscure identifiers as “canoncalize”, “iszero”, or “SIZE_WIDTH” as their own. The advice we currently give to developers is that they need to rewrite their sources accordingly, at least if they use _GNU_SOURCE. Personally, I find this rather questionable.
