1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
|
New parameter parsing functions
===============================
It should be easier to parse input parameters to an extension function.
Hence, borrowing from Python's example, there are now a set of functions
that given the string of type specifiers, can parse the input parameters
and store the results in the user specified variables. This avoids most
of the IS_* checks and convert_to_* conversions. The functions also
check for the appropriate number of parameters, and try to output
meaningful error messages.
Prototypes
----------
/* Implemented. */
int zend_parse_parameters(int num_args TSRMLS_DC, char *type_spec, ...);
int zend_parse_parameters_ex(int flags, int num_args TSRMLS_DC, char *type_spec, ...);
The zend_parse_parameters() function takes the number of parameters
passed to the extension function, the type specifier string, and the
list of pointers to variables to store the results in. The _ex() version
also takes 'flags' argument -- current only ZEND_PARSE_PARAMS_QUIET can
be used as 'flags' to specify that the function should operate quietly
and not output any error messages.
Both functions return SUCCESS or FAILURE depending on the result.
The auto-conversions are performed as necessary. Arrays, objects, and
resources cannot be auto-converted.
Type specifiers
---------------
The following list shows the type specifier, its meaning and the parameter
types that need to be passed by address. All passed paramaters are set
if the PHP parameter is non optional and untouched if optional and the
parameter is not present. The only exception is O where the zend_class_entry*
has to be provided on input and is used to verify the PHP parameter is an
instance of that class.
a - array (zval*)
A - array or object (zval *)
b - boolean (zend_bool)
C - class (zend_class_entry*)
d - double (double)
f - function or array containing php method call info (returned as
zend_fcall_info and zend_fcall_info_cache)
h - array (returned as HashTable*)
H - array or HASH_OF(object) (returned as HashTable*)
l - long (long)
L - long, limits out-of-range numbers to LONG_MAX/LONG_MIN (long)
o - object of any type (zval*)
O - object of specific type given by class entry (zval*, zend_class_entry)
p - valid path (string without null bytes in the middle) and its length (char*, int)
r - resource (zval*)
s - string (with possible null bytes) and its length (char*, int)
z - the actual zval (zval*)
Z - the actual zval (zval**)
* - variable arguments list (0 or more)
+ - variable arguments list (1 or more)
The following characters also have a meaning in the specifier string:
| - indicates that the remaining parameters are optional, they
should be initialized to default values by the extension since they
will not be touched by the parsing function if they are not
passed to it.
/ - use SEPARATE_ZVAL_IF_NOT_REF() on the parameter it follows
! - the parameter it follows can be of specified type or NULL (applies
to all specifiers except for 'b', 'l', and 'd'). If NULL is passed, the
results pointer is set to NULL as well.
Note on 64bit compatibility
---------------------------
Please do not forget that int and long are two different things on 64bit
OSes (int is 4 bytes and long is 8 bytes), so make sure you pass longs to "l"
and ints to strings length (i.e. for "s" you need to pass char * and int),
not the other way round!
Remember: "l" is the only case when you need to pass long (and that's why
it's "l", not "i" btw).
Both mistakes cause memory corruptions and segfaults on 64bit OSes:
1)
char *str;
long str_len; /* XXX THIS IS WRONG!! Use int instead. */
zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s", &str, &str_len)
2)
int num; /* XXX THIS IS WRONG!! Use long instead. */
zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "l", &num)
If you're in doubt, use check_parameters.php script to the parameters
and their types (it can be found in ./scripts/dev/ directory of PHP sources):
# php ./scripts/dev/check_parameters.php /path/to/your/sources/
Examples
--------
/* Gets a long, a string and its length, and a zval */
long l;
char *s;
int s_len;
zval *param;
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "lsz",
&l, &s, &s_len, ¶m) == FAILURE) {
return;
}
/* Gets an object of class specified by my_ce, and an optional double. */
zval *obj;
double d = 0.5;
zend_class_entry *my_ce;
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "O|d",
&obj, my_ce, &d) == FAILURE) {
return;
}
/* Gets an object or null, and an array.
If null is passed for object, obj will be set to NULL. */
zval *obj;
zval *arr;
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "o!a",
&obj, &arr) == FAILURE) {
return;
}
/* Gets a separated array which can also be null. */
zval *arr;
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "a/!",
&arr) == FAILURE) {
return;
}
/* Get either a set of 3 longs or a string. */
long l1, l2, l3;
char *s;
/*
* The function expects a pointer to a integer in this case, not a long
* or any other type. If you specify a type which is larger
* than a 'int', the upper bits might not be initialized
* properly, leading to random crashes on platforms like
* Tru64 or Linux/Alpha.
*/
int length;
if (zend_parse_parameters_ex(ZEND_PARSE_PARAMS_QUIET, ZEND_NUM_ARGS() TSRMLS_CC,
"lll", &l1, &l2, &l3) == SUCCESS) {
/* manipulate longs */
} else if (zend_parse_parameters_ex(ZEND_PARSE_PARAMS_QUIET, ZEND_NUM_ARGS() TSRMLS_CC,
"s", &s, &length) == SUCCESS) {
/* manipulate string */
} else {
/* output error */
return;
}
/* Function that accepts only varargs (0 or more) */
int i, num_varargs;
zval ***varargs = NULL;
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "*", &varargs, &num_varargs) == FAILURE) {
return;
}
for (i = 0; i < num_varargs; i++) {
/* do something with varargs[i] */
}
if (varargs) {
efree(varargs);
}
/* Function that accepts a string, followed by varargs (1 or more) */
char *str;
int str_len;
int i, num_varargs;
zval ***varargs = NULL;
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "s+", &str, &str_len, &varargs, &num_varargs) == FAILURE) {
return;
}
for (i = 0; i < num_varargs; i++) {
/* do something with varargs[i] */
}
if (varargs) {
efree(varargs);
}
/* Function that takes an array, followed by varargs, and ending with a long */
long num;
zval *array;
int i, num_varargs;
zval ***varargs = NULL;
if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "a*l", &array, &varargs, &num_varargs, &num) == FAILURE) {
return;
}
for (i = 0; i < num_varargs; i++) {
/* do something with varargs[i] */
}
if (varargs) {
efree(varargs);
}
|
