Constant: Pre-defined, one-time settable constant for specifying the size of an application's stack space.

CON
   _STACK = Expression

• Expression is an integer expression that indicates the number of longs to reserve for stack space.

Explanation

_STACK is a pre-defined, one-time settable optional constant that specifies the required stack space of an application. This value is added to _FREE if specified, to determine the total amount of stack/free memory space to reserve for a Propeller application. Use _STACK if an application requires a minimum amount of stack space in order to run properly. If the resulting compiled application is too large to allow the specified stack space, an error message will be displayed. For example:

CON
  _STACK = 3000 

The _STACK declaration in the above CON block indicates that the application needs to have at least 3,000 longs of stack space left over after compilation. If the resulting compiled application does not have that much room left over, an error message will indicate by how much it was exceeded. This is a good way to prevent successful compiles of an application that will fail to run properly due to lack of memory.

Note that only the top object file can set the value of _STACK. Any child object's _STACK declarations will be ignored. The stack space reserved by this constant is used by the application's main cog to store temporary data such as call stacks, parameters, and intermediate expression results.