------- Additional Comments From schlie at comcast dot net 2005-05-21 21:28 ------- (In reply to comment #4) > Subject: Re: wrong-code with inlining and type-punned pointer > Because this is what the standard says is allowed. The standard also > says the comparisons and assignment between pointers without a case is > invalid code and should be diagnostic. Again this is what the standard > says for these things and GCC follows the C standard.
Here's an interesting portion of the standard, which seems to direcly imply that signed and unsigned lvalue references are presumed to validly alias; so so this should place both in the same alias set, and potentially eliminate the default warning when comparing pointers which differ only in signness, as it seems a little silly if they may factually alias each other: 6.3 Expressions [#7] An object shall have its stored value accessed only by an lvalue expression that has one of the following types:59 - a type compatible with the effective type of the object, - a qualified version of a type compatible with the effective type of the object, - a type that is the signed or unsigned type corresponding to the effective type of the object, - a type that is the signed or unsigned type corresponding to a qualified version of the effective __________ 59. The intent of this list is to specify those circumstances in which an object may or may not be aliased. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21402