On Sun, 2006-02-19 at 20:43 +0100, Laurent GUERBY wrote: > On Sun, 2006-02-19 at 14:23 -0500, Richard Kenner wrote: > > "Second, for a given integer type (such as > > natural___XDLU_0_2147483647), the type for the nodes in TYPE_MIN_VALUE > > and TYPE_MAX_VALUE really should be a natural___XDLU_0_2147483647. > > ie, the type of an integer constant should be the same as the type of > > its min/max values." > > > > No, the type of the bounds of a subtype should be the *base type*. That's > > how the tree has always looked, as far back as I can remember. > > This is because intermediate computations can produce results > outside the subtype range but within the base type range (RM 3.5(6)), > right? > > type T1 is range 0 .. 127; > -- Compiler will choose some type for T'Base, likely to be -128..127 > -- but could be Integer (implementation dependant) > subtype T is T1 range 0 .. 100; > R : T := 100+X-X; > -- guaranteed work as long 100+X<=T'Base'Last and 100-X>=T'Base'First Which leaves us with a very fundamental issue. Namely that we can not use TYPE_MIN_VALUE or TYPE_MAX_VALUE for ranges. That's lame, incredibly lame. This nonsense really should be isolated within the Ada front-end.
In the mean time, what is the safe way to determine the full set of values any particular object may have, taking into consideration this Ada braindamage? jeff
