gp_debug.h File Reference

A debug message layer. More...

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <unistd.h>
#include <core/gp_compiler.h>

Go to the source code of this file.

Data Structures
struct	gp_debug_msg
	Custom debug message handler structure. More...

Macros
#define	GP_DEBUG(level, ...)    gp_debug_print(level, __FILE__, __FUNCTION__, __LINE__, __VA_ARGS__)
	A debug printf-like macro.
#define	GP_TODO(...)    gp_debug_print(GP_DEBUG_TODO, __FILE__, __FUNCTION__, __LINE__, __VA_ARGS__)
	A debug TODO printf-like macro.
#define	GP_WARN(...)    gp_debug_print(GP_DEBUG_WARN, __FILE__, __FUNCTION__, __LINE__, __VA_ARGS__)
	A debug WARN printf-like macro.
#define	GP_BUG(...)    gp_debug_print(GP_DEBUG_BUG, __FILE__, __FUNCTION__, __LINE__, __VA_ARGS__)
	A debug BUG printf-like macro.
#define	GP_FATAL(...)    gp_debug_print(GP_DEBUG_FATAL, __FILE__, __FUNCTION__, __LINE__, __VA_ARGS__)
	A debug FATAL printf-like macro.

Enumerations
enum	gp_debug_type { GP_DEBUG_TODO = -1 , GP_DEBUG_WARN = -2 , GP_DEBUG_BUG = -3 , GP_DEBUG_FATAL = -4 }
	A debug level constants. More...

Functions
void	gp_debug_print (int level, const char *file, const char *function, int line, const char *fmt,...)
	A debug printf handler.
void	gp_set_debug_level (unsigned int level)
	Sets current debug level.
unsigned int	gp_get_debug_level (void)
	Returns current debug level.
void	gp_set_debug_handler (void(*handler)(const struct gp_debug_msg *msg))
	Redirects debug message into a custom handler.

Detailed Description

A debug message layer.

Many places of the library uses debug messages to report warnings, bugs, or generally important events i.e. pixmap has been allocated, filter function has been called, etc.

Debug messages are printed into the stderr and could be redirected to custom handler.

The debug level can be set by exporting an enviroment variable GP_DEBUG=level.

The verbosity of the messages could be changed by the debug level. The debug level is an unsigned integer (by default set to '0') and only messages that have debug level lower or equal to debug level are printed.

There are few special debug message types with negative debug level (that means that they are always printed), and as so these are used on various error conditions, see below for more information.

Definition in file gp_debug.h.

Macro Definition Documentation

GP_BUG

#define GP_BUG

(

...

)

gp_debug_print(GP_DEBUG_BUG, __FILE__, __FUNCTION__, __LINE__, __VA_ARGS__)

A debug BUG printf-like macro.

Parameters

...	A printf like format string and parameters.

Definition at line 112 of file gp_debug.h.

GP_DEBUG

#define GP_DEBUG	(		level,
			...
	)		gp_debug_print(level, __FILE__, __FUNCTION__, __LINE__, __VA_ARGS__)

A debug printf-like macro.

Parameters

level	A debug level usually between 1 and 10
...	A printf like format string and parameters.

Definition at line 88 of file gp_debug.h.

GP_FATAL

#define GP_FATAL

(

...

)

gp_debug_print(GP_DEBUG_FATAL, __FILE__, __FUNCTION__, __LINE__, __VA_ARGS__)

A debug FATAL printf-like macro.

Parameters

...	A printf like format string and parameters.

Definition at line 120 of file gp_debug.h.

GP_TODO

#define GP_TODO

(

...

)

gp_debug_print(GP_DEBUG_TODO, __FILE__, __FUNCTION__, __LINE__, __VA_ARGS__)

A debug TODO printf-like macro.

Parameters

...	A printf like format string and parameters.

Definition at line 96 of file gp_debug.h.

GP_WARN

#define GP_WARN

(

...

)

gp_debug_print(GP_DEBUG_WARN, __FILE__, __FUNCTION__, __LINE__, __VA_ARGS__)

A debug WARN printf-like macro.

Parameters

...	A printf like format string and parameters.

Definition at line 104 of file gp_debug.h.

Enumeration Type Documentation

gp_debug_type

enum gp_debug_type

A debug level constants.

Messages with debug level 0 are always printed (you should generally avoid using them unless you wan't user to see the message.)

Debug level 1 should be used on object initalization and generally rare and important events.

Debug level > 1 is intended for more verbose reporting, like inner cycles or loop debugging.

Debug levels with negative level are special.

Enumerator
GP_DEBUG_TODO	Not implemented yet. Used in stub functions.
GP_DEBUG_WARN	A warning. Generally a problem that can be ignored.
GP_DEBUG_BUG	A library bug. Library got into an inconsistent state but stil attempts to continue.
GP_DEBUG_FATAL	A fatal condition. Initialization failed Library foo not compiled in

Definition at line 51 of file gp_debug.h.

Function Documentation

gp_debug_print()

void gp_debug_print	(	int	level,
		const char *	file,
		const char *	function,
		int	line,
		const char *	fmt,
			...
	)

A debug printf handler.

Attention

Do not use directly use the GP_DEBUG(), GP_WARN(), ... macros instead.

Parameters

level	A debug level for the mesasge.
file	A file name for the source file the message came from.
function	A function the message came from.
line	A line in the source file the message came from.
fmt	A printf-like format string.
...	A printf-like paramaters.

gp_get_debug_level()

unsigned int gp_get_debug_level

(

void

)

Returns current debug level.

Returns

A current debug level.

gp_set_debug_handler()

void gp_set_debug_handler

(

void(*)(const struct gp_debug_msg *msg)

handler

)

Redirects debug message into a custom handler.

Parameters

handler

A new debug handler. Pass NULL to disable redirection.

gp_set_debug_level()

void gp_set_debug_level

(

unsigned int

level

)

Sets current debug level.

The default debug level is 0 that means that all messages with level up to 0 are printed. To get more verbose debugging pass a value between 1 and 10.

Parameters

level

A new debug level.