# Finding and Reporting Out-of-Bounds Errors

The pointer checker is not supported on macOS* systems.

The pointer checker includes the __chkp_report_control() library function and the `__chkp_report_option_t` enumeration to allow you to control how errors are reported. The function and enumeration are declared in the header file chkp.h.

The report control enumeration has one of the following values:

Enum Value | Action
--- | ---
`__CHKP_REPORT_NONE` | Do nothing.
`__CHKP_REPORT_BPT` | Execute a breakpoint interrupt. If you specify this value, the pointer checker will issue a breakpoint for any out-of-bounds error that it finds. If you are using a debugger, the breakpoint will trap into the debugger so that you can determine where the error occurred. You can then use the features of the debugger to determine the cause of the error.
`__CHKP_REPORT_LOG` | Log the error and continue; the compiler will report each out-of-bounds pointer it finds.
`__CHKP_REPORT_TERM` | Log the error and exit the program; the compiler will only report the first bounds violation and then terminate.
`__CHKP_REPORT_CALLBACK` | Call a user defined function; the compiler will invoke a user-defined function to deal with a bounds error.
`__CHKP_REPORT_TRACEBACK _BPT` | Print a traceback including source file and line number for the instruction where the out-of-bounds error occurred, then execute a breakpoint interrupt. ### Note Specify the traceback compiler option to obtain better traceback information, including routine names.
`__CHKP_REPORT_TRACE_LOG` | Log the error and continue; the log will include traceback information for each out-of-bounds error. This is the default reporting mode. ### Note Specify the traceback compiler option to obtain better traceback information, including routine names.
`__CHKP_REPORT_TRACE_TERM` | Log the error and terminate; the log will include traceback information for each out-of-bounds error. Only the first bounds error will be reported. ### Note Specify the traceback compiler option to obtain better traceback information, including routine names.
`__CHKP_REPORT_TRACE_CALLBACK` | Log the error and call a user-defined routine; the log will include traceback information for each out-of-bounds error. ### Note Specify the traceback compiler option to obtain better traceback information, including routine names.
`__CHKP_REPORT_OOB_STATS` | Emit statistics for the bounds violation; Currently, this is a count of the out-of-bounds errors.
`__CHKP_REPORT_USE_ENV_VAR` | Use the environment variable `INTEL_CHKP_REPORT_MODE` to specify the reporting mode. If the environment variable is not set, the default reporting mode is used.

Changing the Reporting Mode

To change the reporting mode from the default `__CHKP_REPORT_TRACE_LOG`:

1. Include chkp.h in your program source.

2. Add a call to the report control routine `__chkp_report_control()` (before any pointer references are made), specifying one of the enum values.

   For example, to report all bounds errors, specify the following:

       __chkp_report_control(__CHKP_REPORT_LOG, 0);

In the above, the first parameter to the routine is the enum value and the second parameter is 0, except in the case of the `__CHKP_REPORT_CALLBACK` enum value, which requires the name of a user-defined callback routine as the second parameter.

You can also change the reporting mode using the environment variable `INTEL_CHKP_REPORT_MODE`. This allows you to change the reporting mode without recompiling your code. To use the environment variable, do the following:

1. Add an include of chkp.h in your program source.

2. Add a call to the report control routine `__chkp_report_control()` (before any pointer references are made), specifying `__CHKP_REPORT_USE_ENV_VAR`.

3. Set the `INTEL_CHKP_REPORT_MODE` environment variable to the desired report mode. For example:

   `export INTEL_CHKP_REPORT_MODE=__CHKP_REPORT_OOB_STATS`

### Note

The `INTEL_CHKP_REPORT_MODE` environment variable is valid only if a call to `__chkp_report_control` has been made with the report mode set to `__CHKP_REPORT_USE_ENV_VAR`. Otherwise, it is ignored.

If you specify the report mode to be `__CHKP_REPORT_USE_ENV_VAR` and the `INTEL_CHKP_REPORT_MODE` environment variable is not set, the default report mode (`__CHKP_REPORT_TRACE_LOG`) is used.

Parent topic: Using the Pointer Checker

## See Also

/Zi compiler option
traceback, notraceback compiler option