logger.c File Reference

Logging facility, supports verbosity levels. More...

#include <Library/UefiLib.h>
#include <Library/MemoryAllocationLib.h>
#include <UEFIStarter/core/logger.h>

Macros
#define	LOGGER_FORWARD_FUNC(NAME, LEVEL)
	helper macro for quickly defining a callable logging function More...

Functions
LOGLEVEL	get_log_level ()
	Fetches the current log level. More...
LOGLEVEL	set_log_level (LOGLEVEL level)
	Sets a new log level. More...
void	log_print (LOGLEVEL level, CHAR16 *msg)
	Default log writer: prints to text console. More...
static void	_logger_function_va (LOGLEVEL level, UINT16 *message, VA_LIST args)
	internal: formats log message and calls log writer with final string to log. More...
static void EFIAPI	_trace (CHAR16 *fmt,...)
	internal: forwards TRACE messages to internal handler More...
static void EFIAPI	_debug (CHAR16 *fmt,...)
	internal: forwards DEBUG messages to internal handler More...
static void EFIAPI	_info (CHAR16 *fmt,...)
	internal: forwards INFO messages to internal handler More...
static void EFIAPI	_warn (CHAR16 *fmt,...)
	internal: forwards WARN messages to internal handler More...
static void EFIAPI	_error (CHAR16 *fmt,...)
	internal: forwards ERROR messages to internal handler More...
void	reset_logger_entry_counts ()
	Resets all log levels' message counts. More...
UINTN	get_logger_entry_count (LOGLEVEL level)
	Gets a log level's message count. More...
void	kill ()
	Immediately halts the UEFI environment. More...
logger_print_function_t *	set_logger_function (logger_print_function_t *func)
	Sets a new log writer. More...

Variables
const CHAR16 *	logger_level_names [] ={L"",L"ERROR",L"WARN",L"INFO",L"DEBUG",L"TRACE"}
	list of log level's printable names
static int	logging_threshold =TRACE
	current log level; anything higher that won't be logged
static UINTN	logger_entry_counts [TRACE+1]
	numbers of logged messages for each log level
logger_print_function_t *	logger_print_func =log_print
	pointer to the current log writer
const loggers_t	LOG
	The global logging facility. More...

Detailed Description

Logging facility, supports verbosity levels.

Author

Richard Nusser

Copyright

2017-2018 Richard Nusser

License

GPLv3 (see http://www.gnu.org/licenses/)

See also

https://github.com/rinusser/UEFIStarter

Macro Definition Documentation

LOGGER_FORWARD_FUNC

#define LOGGER_FORWARD_FUNC	(		NAME,
			LEVEL
	)

Value:

static void EFIAPI NAME(CHAR16 *fmt, ...) \
{ \
  VA_LIST args; \
  VA_START(args,fmt); \
  _logger_function_va(LEVEL,fmt,args); \
  VA_END(args); \
}

helper macro for quickly defining a callable logging function

Parameters

NAME	the logging function's name
LEVEL	the log level to log at

Function Documentation

get_log_level()

LOGLEVEL get_log_level

(

)

Fetches the current log level.

Returns

the current log level

set_log_level()

LOGLEVEL set_log_level

(

LOGLEVEL

level

)

Sets a new log level.

You can disable logging by calling this with log level "OFF".

Parameters

level

the new log level to use

Returns

the previous log level

log_print()

void log_print	(	LOGLEVEL	level,
		CHAR16 *	msg
	)

Default log writer: prints to text console.

Parameters

level	the log level to log at
msg	the log message, as UTF-16

_logger_function_va()

static void _logger_function_va ( LOGLEVEL  level, UINT16 *  message, VA_LIST  args  )

static

internal: formats log message and calls log writer with final string to log.

This function uses the same format strings as the Print() functions.

Parameters

level	the log level to log at
message	the message's format string
args	the vararg list of parameters matching matching the format string's placeholder

_trace()

static void EFIAPI _trace ( CHAR16 *  fmt,   ...  )

static

internal: forwards TRACE messages to internal handler

Parameters

fmt	the log entry's format string
...	any additional parameters to be formatted

_debug()

static void EFIAPI _debug ( CHAR16 *  fmt,   ...  )

static

internal: forwards DEBUG messages to internal handler

Parameters

fmt	the log entry's format string
...	any additional parameters to be formatted

_info()

static void EFIAPI _info ( CHAR16 *  fmt,   ...  )

static

internal: forwards INFO messages to internal handler

Parameters

fmt	the log entry's format string
...	any additional parameters to be formatted

_warn()

static void EFIAPI _warn ( CHAR16 *  fmt,   ...  )

static

internal: forwards WARN messages to internal handler

Parameters

fmt	the log entry's format string
...	any additional parameters to be formatted

_error()

static void EFIAPI _error ( CHAR16 *  fmt,   ...  )

static

internal: forwards ERROR messages to internal handler

Parameters

fmt	the log entry's format string
...	any additional parameters to be formatted

reset_logger_entry_counts()

void reset_logger_entry_counts

(

)

Resets all log levels' message counts.

Used e.g. by the test framework to detect which tests generated errors.

get_logger_entry_count()

UINTN get_logger_entry_count

(

LOGLEVEL

level

)

Gets a log level's message count.

Parameters

level

the log level to get the count for

Returns

the number of logged messages at the given level since the last reset

kill()

void kill

(

)

Immediately halts the UEFI environment.

Use this to e.g. debug issues in graphical animations where it's vital to stop everything before the target gets painted over.

Technically the emitted interrupt 3 is usually used for debuggers but the UEFI specification requires INT 3 to be unassigned by default, thus halting everything. If you use this function with a debugger attached this will probably trigger the debugger instead.

set_logger_function()

logger_print_function_t* set_logger_function

(

logger_print_function_t *

func

)

Sets a new log writer.

Use this to replace the built-in text mode writer, e.g. to output log messages in a graphical environment

Parameters

func	the new log writer function

Returns

the previous log writer function

Variable Documentation

LOG

const loggers_t LOG

Initial value:

={
  .trace=_trace,
  .debug=_debug,
  .info=_info,
  .warn=_warn,
  .error=_error
}

The global logging facility.

This contains function pointers for each log level, so users can call e.g. LOG.debug() to log a debug message.