#include <sys/syslog.h>

sys/syslog.h Kernel.framework

includes: sys/appleapiopts.h, sys/cdefs.h, Kernel/stdarg.h

2 structs · 1 macro · 1 function

macroLOG_PRINTF

#define LOG_PRINTF -1

pseudo-priority to indicate use of printf

structreg_values

size 16, align 8

unsigned int	rv_value
char *	rv_name

structreg_desc

register descriptors are used for formatted prints of register values rd_mask and rd_shift must be defined, other entries may be null

size 32, align 8

unsigned int	rd_mask	mask to extract field
int	rd_shift	shift for extracted value, - >>, + <<
char *	rd_name	field name
char *	rd_format	format to print field
struct reg_values *	rd_values	symbolic names of values

functionlog

__printflike(2, 3)
void log(int, const char *, ...)

▾

claude-fable-5, 2026-08-23 · not from Apple sources · verified against xnu osfmk/kern/debug.c

Kernel logging routine in the style of syslog(3): formats the message printf-style and delivers it to the console and to the os_log system (OS_LOG_DEFAULT), where it is visible to log(1) and Console. The level argument (LOG_ERR, LOG_WARNING, ...) is currently ignored. Preemption is disabled while writing to the console.