Hans-Peter Nilsson wrote: > There's background in > <http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36593>. Neither > Richi nor me could find the union-assignment "gcc extension" at > a glance, probably because it's not an *extension* but an > implementation-defined behavior, and actually duly documented as > such. However, to cross-reference that section together with > the clarifying type-punning blurb in the -fstrict-aliasing > documentation seems would be an improvement, and apparently > there's enough confusion about casting, pointers and unions to > call for an extra example, covering the offending code in the > PR. > > So far the RFA. The RFC is whether (to reject this patch and > call for another) to allow the cast-through-pointer-to-union in > the example and the PR as a variant of the blessed > implementation-defined type-punning using unions. IMHO not, but > the offending code is from a canonical strtod implementation > imported into newlib, and enough people are confused already,
I thought cast-through-pointer-to-union didn't work and was already disallowed; we've been around all this already. This patch of yours already documents uncontroversial behaviour. I don't like the phrase "might not work". It's better just to say "is not allowed". Andrew.
