On Apr 17, 2015, at 1:52 PM, Steve Ellcey <[email protected]> wrote:
> struct link_namespaces *ns = &_dl_ns[nsid];
> (nsid != 0) ? (void) (0) : bad ("nsid != 0”);
Without disagreeing with the fact this looks like a bug, ideally, the two lines
above would be switched:
c++98:
If both the pointer operand and the result point to elements
of the same array object, or one past the last element of the array
object, the evaluation shall not produce an overflow; otherwise, the
behavior is undefined.
and c99 tc3:
8 When an expression that has integer type is added to or subtracted from a
pointer, the
result has the type of the pointer operand. If the pointer operand points
to an element of
an array object, and the array is large enough, the result points to an
element offset from
the original element such that the difference of the subscripts of the
resulting and original
array elements equals the integer expression. In other words, if the
expression P points to
the i-th element of an array object, the expressions (P)+N (equivalently,
N+(P)) and
(P)-N (where N has the value n) point to, respectively, the i+n-th and
i-n-th elements of
the array object, provided they exist. Moreover, if the expression P points
to the last
element of an array object, the expression (P)+1 points one past the last
element of the
array object, and if the expression Q points one past the last element of
an array object,
the expression (Q)-1 points to the last element of the array object. If
both the pointer
operand and the result point to elements of the same array object, or one
past the last
element of the array object, the evaluation shall not produce an overflow;
otherwise, the
behavior is undefined.
