"Manuel López-Ibáñez" <[EMAIL PROTECTED]> writes: >> >> Another approach would be to only use the carets for parse errors, >> >> which is where they are the most helpful. For a middle-end error like >> >> "assuming signed overflow does not occur when simplifying >> >> multiplication" a caret pointer might be more misleading than >> >> otherwise, as one thing we know for sure is that it would not point at >> >> a multiplication operator. >> >> >> > >> > I don't get this. So, what is it pointing to? >> >> >> I don't know for sure. I would guess that it would point to the start >> of the statement in which the overflow is found. The warning is going >> to use the location from some statement being simplified, not from the >> operator. >> > > Why? Isn't the operator available at that point?
The location information, if present, is technically available, but it would require some surgery to actually get it. The warning is queued up in fold_binary, which does not have access to the location and is often called in cases where there is no obvious location--because it is optimizing some other expression. The warning is not issued at that point. It is only issued later, when we know whether the folding caused some actual simplification in the statement. At that point we also don't know the specific location. As we move to tuples, we will have even less location information at this point. We will almost certainly not have the location of any operators. This is in general a good thing, as we won't be paying the memory space to carry them through the whole middle-end. Ian
