Random C idea: limited integers
I wonder if this could be added to gcc
int a __attribute__((limited));
So if a every overflows or underflows, the machine will
will check, perhaps by raising a SIGTRAP.
How much would it cost in performance? At the worst, one conditional branch operation after each manipulation of such a variable, to check the overflow status bit. But probably only one or two additional instructions, if we only care about limiting to the size of the variable and not an arbitrary range. Maybe something more efficient is possible.
The goal is to prevent the significant class of bugs caused by an integer overflow without necessarily having a following array overflow.
This probably needs to be optional per-variable so as not to break existing code.
Maybe this has already been done or it isn't feasible or it's just silly?
posted Sat 23 Oct 2004 in /software/languages/C | link
Archives 2008: Apr Feb 2007: Jul May Feb Jan 2006: Dec Nov Oct Sep Aug Jul Jun Jan 2005: Sep Aug Jul Jun May Apr Mar Feb Jan 2004: Dec Nov Oct Sep Aug Jul Jun May Apr Mar Feb Jan 2003: Dec Nov Oct Sep Aug Jul Jun May
Copyright (C) 1999-2007 Martin Pool.