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  Pragma:    check_stack
 
  Syntax:    #pragma check_stack ([{ on | off }])
 
  Summary:   Instructs the compiler to turn off stack probes if off is
             specified, or to turn on stack probes if on is specified.
             If no argument is given, stack probes are treated
             according to the default (on, unless /Gs was used).
 
  See also:  check_pointer
 
     You can reduce the size of a program and speed up execution
     slightly by removing stack probes. You can do this with either the
     /Gs option or the check_stack pragma.
 
     A "stack probe" is a short routine called on entry to a function
     to verify that there is enough room in the program stack to
     allocate local variables required by the function. The stack probe
     routine is called at every function entry point. Ordinarily, the
     stack probe routine generates a stack overflow message when it
     determines that the required stack space is not available. When
     stack checking is turned off, the stack probe routine is not
     called, and stack overflow can occur without being diagnosed
     (i.e., no error message is printed).
 
     Use the /Gs option when you want to turn off stack checking for an
     entire module if you know that the program does not exceed the
     available stack space. For example, stack probes may not be needed
     for programs that make very few function calls, or that have only
     modest local variable requirements. In the absence of the /Gs
     option, stack checking is on.
 
     Use the check_stack pragma when you want to turn stack checking on
     or off for selected routines only, leaving the default (as
     determined by the presence or absence of the /Gs option) for the
     rest. When you want to turn off stack checking, put the following
     line before the definition of the function that you do not want to
     check:
 
          #pragma check_stack( off )
 
     Note that the preceding line disables stack checking for all
     routines that follow it in the source file, not just the routines
     on the same line. To reinstate stack checking, insert the
     following line:
 
          #pragma check_stack( on )
 
     For earlier versions of Microsoft C, the check_stack pragma had a
     different format: check_stack+ to enable stack checking and
     check_stack- to disable stack checking. Although the Microsoft C
     compiler still accepts this format, its use is discouraged, since
     it may not be supported in future versions.
 
     If no argument is given for the check_stack pragma, stack checking
     reverts to the behavior specified on the command line: disabled if
     the /Gs option is given, or enabled if otherwise. The interaction
     of the check_stack pragma with the /Gs option is explained in
     greater detail below:
 
                                  Compiled with
     Syntax                       /Ox or /Ol?     Action
 
     #pragma check_stack()        Yes             Turns off stack
                                                  checking for routines
                                                  that follow
 
     #pragma check_stack()        No              Turns on stack
                                                  checking for routines
                                                  that follow
 
     #pragma check_stack( on )    Yes or no       Turns on stack
                                                  checking for routines
                                                  that follow
 
     #pragma check_stack( off )   Yes or no       Turns off stack
                                                  checking for routines
                                                  that follow
 
     The check_stack( off ) and /Gs options should be used with great
     care. Although these options can make a program smaller and
     faster, they may mean that the program will not be able to detect
     certain execution errors.
                                    -♦-