Search results
Results From The WOW.Com Content Network
Initialized does not mean correct if the value is a default one. (However, default initialization to 0 is a right practice for pointers and arrays of pointers, since it makes them invalid before they are actually initialized to their correct value.) In C, variables with static storage duration that are not initialized explicitly are initialized ...
Wild pointers, also called uninitialized pointers, arise when a pointer is used prior to initialization to some known state, which is possible in some programming languages. They show the same erratic behavior as dangling pointers, though they are less likely to stay undetected because many compilers will raise a warning at compile time if ...
Modern programming languages like C and C++ have powerful features of explicit memory management and pointer arithmetic. These features are designed for developing efficient applications and system software. However, using these features incorrectly may lead to memory corruption errors.
In C++, because dereferencing a null pointer is undefined behavior, compiler optimizations may cause other checks to be removed, leading to vulnerabilities elsewhere in the code. [ 29 ] [ 30 ] Some lists may also include race conditions (concurrent reads/writes to shared memory) as being part of memory safety (e.g., for access control).
Dereferencing any of these variables could cause a segmentation fault: dereferencing the null pointer generally will cause a segfault, while reading from the wild pointer may instead result in random data but no segfault, and reading from the dangling pointer may result in valid data for a while, and then random data as it is overwritten.
Uninitialized data, both variables and constants, is instead in the BSS segment. Historically, to be able to support memory address spaces larger than the native size of the internal address register would allow, early CPUs implemented a system of segmentation whereby they would store a small set of indexes to use as offsets to certain areas.
Used by Microsoft's C++ debugging runtime library and many DOS environments to mark uninitialized stack memory. CC is the opcode of the INT 3 debug breakpoint interrupt on x86 processors. [30] CDCDCDCD: Used by Microsoft's C/C++ debug malloc() function to mark uninitialized heap memory, usually returned from HeapAlloc() [26] 0D15EA5E
In C++, a constructor of a class/struct can have an initializer list within the definition but prior to the constructor body. It is important to note that when you use an initialization list, the values are not assigned to the variable. They are initialized. In the below example, 0 is initialized into re and im. Example: