Magic
[Tools]
Eina_Magic provides run-time type-checking.
More...Defines | |
#define | EINA_MAGIC_NONE 0x1234fedc |
Random value for specifying that a structure using the magic feature has already been freed. | |
#define | EINA_MAGIC Eina_Magic __magic; |
Declaration of a variable of type Eina_Magic. | |
#define | EINA_MAGIC_SET(d, m) (d)->__magic = (m) |
Set the magic number of d to m . | |
#define | EINA_MAGIC_CHECK(d, m) ((d) && ((d)->__magic == (m))) |
Test if d is NULL or not, and if not NULL , if d->__eina_magic is equal to m . | |
#define | EINA_MAGIC_FAIL(d, m) |
Call eina_magic_fail() with the parameters d , d->__magic , m , __FILE__, __FUNCTION__ and __LINE__. | |
Typedefs | |
typedef unsigned int | Eina_Magic |
An abstract type for a magic number. | |
Functions | |
const char * | eina_magic_string_get (Eina_Magic magic) |
Return the string associated to the given magic identifier. | |
Eina_Bool | eina_magic_string_set (Eina_Magic magic, const char *magic_name) |
Set the string associated to the given magic identifier. | |
Eina_Bool | eina_magic_string_static_set (Eina_Magic magic, const char *magic_name) |
Set the string associated to the given magic identifier. | |
void | eina_magic_fail (void *d, Eina_Magic m, Eina_Magic req_m, const char *file, const char *fnc, int line) |
Display a message or abort if a magic check failed. | |
Variables | |
Eina_Error | EINA_ERROR_MAGIC_FAILED |
Error identifier corresponding to magic check failure. |
Detailed Description
Eina_Magic provides run-time type-checking.C is a weak statically typed language, in other words, it will just check for types during compile time and any cast will make the compiler believe the type is correct.
In real world code we often need to deal with casts, either explicit or implicit by means of void*
. We also need to resort to casts when doing inheritance in C.
Eina_Magic give us a way to do casts and still be certain of the type we are opearting on.
- Note:
- It should be noted that it is considered good practice to disable Eina_Magic for production code. The reasoning is that any Eina_Magic errors should have been caught during testing and therefore there is no reason to incur the performance downside of Eina_Magic.
Define Documentation
#define EINA_MAGIC_NONE 0x1234fedc |
Random value for specifying that a structure using the magic feature has already been freed.
It is used by eina_magic_fail().
If the magic feature of Eina is disabled, EINA_MAGIC_NONE is just 0
.
Referenced by eina_magic_fail(), eina_matrixsparse_free(), eina_rectangle_pool_free(), eina_rectangle_pool_release(), and eina_simple_xml_attribute_free().
#define EINA_MAGIC Eina_Magic __magic; |
Declaration of a variable of type Eina_Magic.
To put in a structure when one wants to use the magic feature of Eina with the functions of that structure, like that:
struct Foo { int i; EINA_MAGIC };
If the magic feature of Eina is disabled, EINA_MAGIC does nothing.
#define EINA_MAGIC_SET | ( | d, | |||
m | ) | (d)->__magic = (m) |
Set the magic number of d
to m
.
d
must be a valid pointer to a structure holding an Eina magic number declaration. Use EINA_MAGIC to add such declaration.
If the magic feature of Eina is disabled, EINA_MAGIC_CHECK is just the value 0
.
Referenced by eina_array_accessor_new(), eina_array_iterator_new(), eina_array_new(), eina_array_step_set(), eina_file_direct_ls(), eina_file_ls(), eina_file_stat_ls(), eina_hash_iterator_data_new(), eina_hash_iterator_key_new(), eina_hash_iterator_tuple_new(), eina_hash_new(), eina_inarray_accessor_new(), eina_inarray_iterator_new(), eina_inarray_iterator_reversed_new(), eina_inlist_accessor_new(), eina_inlist_iterator_new(), eina_list_accessor_new(), eina_list_iterator_new(), eina_list_iterator_reversed_new(), eina_matrixsparse_free(), eina_matrixsparse_iterator_complete_new(), eina_matrixsparse_iterator_new(), eina_matrixsparse_new(), eina_rectangle_pool_free(), eina_rectangle_pool_new(), eina_rectangle_pool_release(), eina_rectangle_pool_request(), eina_simple_xml_attribute_free(), eina_simple_xml_attribute_new(), eina_simple_xml_node_load(), eina_simple_xml_node_tag_new(), eina_tile_grid_slicer_iterator_new(), eina_tiler_iterator_new(), eina_tiler_new(), eina_xattr_fd_ls(), eina_xattr_ls(), eina_xattr_value_fd_ls(), and eina_xattr_value_ls().
#define EINA_MAGIC_CHECK | ( | d, | |||
m | ) | ((d) && ((d)->__magic == (m))) |
Test if d
is NULL
or not, and if not NULL
, if d->__eina_magic
is equal to m
.
d
must be a structure that holds an Eina magic number declaration. Use EINA_MAGIC to add such declaration.
If the magic feature of Eina is disabled, EINA_MAGIC_CHECK is just the value 1
.
#define EINA_MAGIC_FAIL | ( | d, | |||
m | ) |
Value:
eina_magic_fail((void *)(d), \ (d) ? (d)->__magic : 0, \ (m), \ __FILE__, \ __FUNCTION__, \ __LINE__);
d
, d->__magic
, m
, __FILE__, __FUNCTION__ and __LINE__.
d
must be a structure that holds an Eina magic number declaration. Use EINA_MAGIC to add such declaration.
If the magic feature of Eina is disabled, EINA_MAGIC_FAIL does nothing.
Function Documentation
const char* eina_magic_string_get | ( | Eina_Magic | magic | ) |
Return the string associated to the given magic identifier.
- Parameters:
-
magic The magic identifier.
- Returns:
- The string associated to the identifier.
magic
. Even if none are found this function still returns non NULL
, in this case an identifier such as "(none)", "(undefined)" or "(unknown)".The following identifiers may be returned whenever magic is invalid, with their meanings:
- (none): no magic was registered exists at all.
- (undefined): magic was registered and found, but no string associated.
- (unknown): magic was not found in the registry.
- Warning:
- The returned value must not be freed.
Referenced by eina_magic_fail().
Eina_Bool eina_magic_string_set | ( | Eina_Magic | magic, | |
const char * | magic_name | |||
) |
Set the string associated to the given magic identifier.
- Parameters:
-
magic The magic identifier. magic_name The string associated to the identifier, must not be NULL
.
- Returns:
- EINA_TRUE on success, EINA_FALSE on failure.
magic_name
to magic
. It is not checked if number or string are already set, in which case you will end with duplicates. Internally, eina will make a copy of magic_name
.
- See also:
- eina_magic_string_static_set()
References EINA_FALSE, EINA_SAFETY_ON_NULL_RETURN_VAL, and EINA_TRUE.
Eina_Bool eina_magic_string_static_set | ( | Eina_Magic | magic, | |
const char * | magic_name | |||
) |
Set the string associated to the given magic identifier.
- Parameters:
-
magic The magic identifier. magic_name The string associated to the identifier, must not be NULL
.
- Returns:
- EINA_TRUE on success, EINA_FALSE on failure.
magic_name
to magic
. It is not checked if number or string are already set, in which case you might end with duplicates. Eina will not make a copy of magic_name
, this means that magic_name
has to be a valid pointer for as long as magic
is used.
- See also:
- eina_magic_string_set()
References EINA_FALSE, EINA_SAFETY_ON_NULL_RETURN_VAL, and EINA_TRUE.
void eina_magic_fail | ( | void * | d, | |
Eina_Magic | m, | |||
Eina_Magic | req_m, | |||
const char * | file, | |||
const char * | fnc, | |||
int | line | |||
) |
Display a message or abort if a magic check failed.
- Parameters:
-
d The checked data pointer. m The magic identifer to check. req_m The requested magic identifier to check. file The file in which the magic check failed. fnc The function in which the magic check failed. line The line at which the magic check failed.
- Warning:
- You should strongly consider using EINA_MAGIC_FAIL(d, m) instead.
- If
d
isNULL
, a message warns about aNULL
pointer. - Otherwise, if
m
is equal to EINA_MAGIC_NONE, a message warns about a handle that was already freed. - Otherwise, if
m
is equal toreq_m
, a message warns about a handle that is of wrong type. - Otherwise, a message warns you about ab-using that function...
References eina_error_set(), EINA_LOG_DOMAIN_GLOBAL, EINA_LOG_LEVEL_CRITICAL, eina_log_print(), EINA_MAGIC_NONE, and eina_magic_string_get().