Runtime Checking (RTC) is a dbx feature that consists of two parts: memory access checking and memory use/leaks checking. Memory access checking is available only on SPARC platforms
Access checking checks for improper use of memory by the debugged application. RTC monitors memory accesses (loads, stores, and free operations) and also detects memory leaks (allocations of malloc() (heap) space that are not freed and yhat have no pointers referencing them).
Access checking enables you to find loads or stores to out-of-range memory (operations that might show up unpredictably as a BUS errors or segmentation violations); loads and stores using in-range memory that has been deallocated (either through a free() call, for heap memory, or through a function return, for stack memory); loads from in-range memory that has not been initialized; and improper free() calls such as duplicate free()'s or free()'s of non-malloc() space.
Memory use/leak checking involves keeping track of all the outstanding heap space and then on demand or at termination of the program, scanning the available data spaces and identifying the space that has no references.
Fortran users should consider using the -stackvar option to take full advantage of RTC. See the Fortran User's Guide for information on how to use -stackvar.