Good old calloc(size_t n, size_t s) still allocates a zero'd array of n objects of size s, but C23 requires that it return a null pointer if n*s would overflow. ![]() The new memset_explicit() function is for erasing sensitive in-memory data unlike ordinary memset, it is intended to prevent optimizations from eliding the erasure. The ckd_* macros steer a refreshingly sane path around arithmetic pitfalls including C's "usual arithmetic conversions."Ĭ23 also adds new features to protect secrets from prying eyes and programmers from themselves. Similar macros handle multiplication and subtraction. The type-generic macro ckd_add() computes the sum of ul and sc "as if both operands were represented in a signed integer type with infinite range." If the mathematically correct sum fits into a signed int, it is stored in i and the macro returns false, indicating "no surprise" otherwise, i ends up with the sum wrapped in a well-defined way and the macro returns true. ![]() For example, the new header standardizes checked integer arithmetic: The most important, if not the most exciting, make it easier to write safe, correct, and secure code. Like the previous major revision, C11, 7 the latest standard introduces several useful features. Sidebars celebrate C idioms and undefined behavior with code and song, respectively. We'll tour the highs and lows of the latest draft 9 and then drill down on the mother of all breaking changes. Sets the World on Fire Terence Kelly with Special Guest Borer Yekai PanĪ new major revision of the C language standard, C23, is due out this year.
0 Comments
Leave a Reply. |