# OS_EnableCallTrace

## C Specification

  `#include <nitro/os.h>`
  `BOOL OS_EnableCallTrace( void );`

## Arguments

None.

## Return Values

The status before this function was called. TRUE indicates that it was enabled. FALSE indicates that it was disabled.

## Description

This function enables the function call trace feature.

This switch decides whether the function entry and exit (`__PROFILE_ENTRY`, `__PROFILE_EXIT`) that are inserted by the `profile` feature will become enabled. Therefore when you use the function call trace feature in stack mode, take note of how you time enable / disable switching. For example, if you call a function called `test()` when in disabled status, and then enable from within the `test()` function, consistency will not be possible because the function will attempt to discard information from the stack at `__PROFILE_EXIT`, even though nothing was done at the function entry (`__PROFILE_ENTRY`). Log mode only obtains records at `__PROFILE_ENTRY`, and therefore you can change status at any point.

Enable switches are set for each trace buffer. Therefore one will not enable all.

If this function is compiled for debugging, it will function properly. However, if compiled for the final ROM version (`FINALROM`) library, it will not do anything.

## See Also

`OS_InitCallTrace, OS_DisableCallTrace, OS_RestoreCallTrace
`

## Revision History

04/23/2004 Initial Version