Gem #151

Abstract

Let's get started? Integer overflows are exotic and dangerous beasts, that most programmers do not encounter very often, and tend to forget about. An integer overflow occurs when the result of an arithmetic computation does not fit in the machine integer type that needs to hold the result. Of course, Ada requires run-time checks to protect against integer overflows, which are enabled by the switch -gnato in GNAT. But it is common to compile without this switch for production binaries, in which case an integer overflow will result in what the Ada Reference Manual calls "erroneous behavior", which means that anything could happen (see Gems #132 to #135).