Memory Leak Errors

With leak checking turned on, runtime checking reports the following types of errors.

Address in Block (aib) Error

Problem: A possible memory leak. There is no reference to the start of an allocated block, but there is at least one reference to an address within the block.

Possible causes: The only pointer to the start of the block is incremented.

Example;

char *ptr;
main()
{
   ptr = (char *)malloc(4);
   ptr++;    /* Address in Block */
}

Address in Register (air) Error

Problem: A possible memory leak. An allocated block has not been freed, and no reference to the block exists anywhere in program memory, but a reference exists in a register.

Possible causes: This can occur legitimately if the compiler keeps a program variable only in a register instead of in memory. The compiler often does this for local variables and function parameters when optimization is turned on. If this error occurs when optimization has not been turned on, it is likely to be an actual memory leak. This can occur if the only pointer to an allocated block goes out of scope before the block is freed.

Example:

if (i == 0) {
       char *ptr = (char *)malloc(4);
       /* ptr is going out of scope */
}
  /* Memory Leak or Address in Register */

Memory Leak (mel) Error

Problem: An allocated block has not been freed, and no reference to the block exists anywhere in the program.

Possible causes: Program failed to free a block no longer used.

Example:

char *ptr;

    ptr = (char *)malloc(1);
    ptr = 0;
/* Memory leak (mel) */