<!--
{
  "documentType" : "article",
  "framework" : "os",
  "identifier" : "/documentation/os/deprecated-symbols",
  "metadataVersion" : "0.1.0",
  "role" : "collectionGroup",
  "title" : "Deprecated Symbols"
}
-->

# Deprecated Symbols

Review unsupported symbols and their replacements.

## Topics

### Deprecated Functions

[`extern bool os_log_is_enabled(os_log_t log);`](/documentation/os/os_log_is_enabled)

[`extern bool os_log_is_debug_enabled(os_log_t log);`](/documentation/os/os_log_is_debug_enabled)

[`extern unsigned int os_activity_get_active(os_activity_id_t *entries, unsigned int *count);`](/documentation/os/os_activity_get_active)

Returns the stack of nested activities associated with the current thread.

[`extern void os_activity_end(os_activity_t activity);`](/documentation/os/os_activity_end)

Ends the specified activity on the current thread.

[`func os_trace_debug_enabled() -> Bool`](/documentation/os/os_trace_debug_enabled())

Returns whether debug level trace information is enabled.

[`func os_trace_info_enabled() -> Bool`](/documentation/os/os_trace_info_enabled())

Returns whether info level trace information is enabled.

[`func os_trace_type_enabled(UInt8) -> Bool`](/documentation/os/os_trace_type_enabled(_:))

Returns whether the specified info level trace information is enabled.

### Deprecated Macros

[`#define os_activity_start(description, flags)`](/documentation/os/os_activity_start)

[`#define os_activity_set_breadcrumb(name)`](/documentation/os/os_activity_set_breadcrumb)

Flags the current activity as a breadcrumb, to signify an interesting event.

[`var OS_TRACE_TYPE_DEBUG: UInt32`](/documentation/os/OS_TRACE_TYPE_DEBUG)

Trace messages that occur when a debugger is attached.

[`var OS_TRACE_TYPE_INFO: UInt32`](/documentation/os/OS_TRACE_TYPE_INFO)

Trace messages that occur when a debugger is attached and additional info is requested.

[`var OS_TRACE_TYPE_RELEASE: UInt32`](/documentation/os/OS_TRACE_TYPE_RELEASE)

Trace messages to be captured on your app when instealled on a user’s device.

### Deprecated Type Aliases

[`typedef uint32_t os_breadcrumb_t;`](/documentation/os/os_breadcrumb_t)

[`typedef void (^)(NSObject<OS_xpc_object> *) os_trace_payload_t;`](/documentation/os/os_trace_payload_t)

A pointer to a trace payload.

[`typealias os_trace_payload_object_t`](/documentation/os/os_trace_payload_object_t)

A pointer to a trace payload object.


---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)