1New parameter parsing functions 2=============================== 3 4It should be easier to parse input parameters to an extension function. 5Hence, borrowing from Python's example, there are now a set of functions 6that given the string of type specifiers, can parse the input parameters 7and store the results in the user specified variables. This avoids most 8of the IS_* checks and convert_to_* conversions. The functions also 9check for the appropriate number of parameters, and try to output 10meaningful error messages. 11 12 13Prototypes 14---------- 15/* Implemented. */ 16int zend_parse_parameters(int num_args, char *type_spec, ...); 17int zend_parse_parameters_ex(int flags, int num_args, char *type_spec, ...); 18 19The zend_parse_parameters() function takes the number of parameters 20passed to the extension function, the type specifier string, and the 21list of pointers to variables to store the results in. The _ex() version 22also takes 'flags' argument -- current only ZEND_PARSE_PARAMS_QUIET can 23be used as 'flags' to specify that the function should operate quietly 24and not output any error messages. 25 26Both functions return SUCCESS or FAILURE depending on the result. 27 28The auto-conversions are performed as necessary. Arrays, objects, and 29resources cannot be auto-converted. 30 31PHP 5.5 includes a new function: 32 33int zend_parse_parameter(int flags, int arg_num, zval **arg, const char *spec, ...); 34 35This function behaves like zend_parse_parameters_ex() except that instead of 36reading the arguments from the stack, it receives a single zval to convert 37(passed with double indirection). The passed zval may be changed in place as 38part of the conversion process. 39 40See also https://wiki.php.net/rfc/zpp_improv#expose_zend_parse_arg_as_zend_parse_parameter 41 42 43Type specifiers 44--------------- 45 The following list shows the type specifier, its meaning and the parameter 46 types that need to be passed by address. All passed parameters are set 47 if the PHP parameter is non optional and untouched if optional and the 48 parameter is not present. The only exception is O where the zend_class_entry* 49 has to be provided on input and is used to verify the PHP parameter is an 50 instance of that class. 51 52 a - array (zval*) 53 A - array or object (zval*) 54 b - boolean (zend_bool) 55 C - class (zend_class_entry*) 56 d - double (double) 57 f - function or array containing php method call info (returned as 58 zend_fcall_info and zend_fcall_info_cache) 59 h - array (returned as HashTable*) 60 H - array or HASH_OF(object) (returned as HashTable*) 61 l - long (zend_long) 62 L - long, limits out-of-range numbers to LONG_MAX/LONG_MIN (zend_long, ZEND_LONG_MAX/ZEND_LONG_MIN) 63 o - object of any type (zval*) 64 O - object of specific type given by class entry (zval*, zend_class_entry) 65 p - valid path (string without null bytes in the middle) and its length (char*, size_t) 66 P - valid path (string without null bytes in the middle) as zend_string (zend_string*) 67 r - resource (zval*) 68 s - string (with possible null bytes) and its length (char*, size_t) 69 S - string (with possible null bytes) as zend_string (zend_string*) 70 z - the actual zval (zval*) 71 * - variable arguments list (0 or more) 72 + - variable arguments list (1 or more) 73 74 The following characters also have a meaning in the specifier string: 75 | - indicates that the remaining parameters are optional, they 76 should be initialized to default values by the extension since they 77 will not be touched by the parsing function if they are not 78 passed to it. 79 / - use SEPARATE_ZVAL_IF_NOT_REF() on the parameter it follows 80 ! - the parameter it follows can be of specified type or NULL. If NULL is 81 passed and the output for such type is a pointer, then the output 82 pointer is set to a native NULL pointer. 83 For 'b', 'l' and 'd', an extra argument of type zend_bool* must be 84 passed after the corresponding bool*, zend_long* or double* arguments, 85 respectively. A non-zero value will be written to the zend_bool if a 86 PHP NULL is passed. 87 88 89Note on 64bit compatibility 90--------------------------- 91Please note that since version 7 PHP uses zend_long as integer type and 92zend_string with size_t as length, so make sure you pass zend_longs to "l" 93and size_t to strings length (i.e. for "s" you need to pass char * and size_t), 94not the other way round! 95 96Both mistakes might cause memory corruptions and segfaults: 971) 98 char *str; 99 long str_len; /* XXX THIS IS WRONG!! Use size_t instead. */ 100 zend_parse_parameters(ZEND_NUM_ARGS(), "s", &str, &str_len) 101 1022) 103 int num; /* XXX THIS IS WRONG!! Use zend_long instead. */ 104 zend_parse_parameters(ZEND_NUM_ARGS(), "l", &num) 105 106If you're in doubt, use check_parameters.php script to the parameters 107and their types (it can be found in ./scripts/dev/ directory of PHP sources): 108 109# php ./scripts/dev/check_parameters.php /path/to/your/sources/ 110 111 112Examples 113-------- 114/* Gets a long, a string and its length, and a zval */ 115zend_long l; 116char *s; 117size_t s_len; 118zval *param; 119if (zend_parse_parameters(ZEND_NUM_ARGS(), "lsz", 120 &l, &s, &s_len, ¶m) == FAILURE) { 121 return; 122} 123 124 125/* Gets an object of class specified by my_ce, and an optional double. */ 126zval *obj; 127double d = 0.5; 128zend_class_entry *my_ce; 129if (zend_parse_parameters(ZEND_NUM_ARGS(), "O|d", 130 &obj, my_ce, &d) == FAILURE) { 131 return; 132} 133 134 135/* Gets an object or null, and an array. 136 If null is passed for object, obj will be set to NULL. */ 137zval *obj; 138zval *arr; 139if (zend_parse_parameters(ZEND_NUM_ARGS(), "o!a", 140 &obj, &arr) == FAILURE) { 141 return; 142} 143 144 145/* Gets a separated array which can also be null. */ 146zval *arr; 147if (zend_parse_parameters(ZEND_NUM_ARGS(), "a/!", 148 &arr) == FAILURE) { 149 return; 150} 151 152/* Get either a set of 3 longs or a string. */ 153zend_long l1, l2, l3; 154char *s; 155/* 156 * The function expects a pointer to a size_t in this case, not a long 157 * or any other type. If you specify a type which is larger 158 * than a 'size_t', the upper bits might not be initialized 159 * properly, leading to random crashes on platforms like 160 * Tru64 or Linux/Alpha. 161 */ 162size_t length; 163 164if (zend_parse_parameters_ex(ZEND_PARSE_PARAMS_QUIET, ZEND_NUM_ARGS(), 165 "lll", &l1, &l2, &l3) == SUCCESS) { 166 /* manipulate longs */ 167} else if (zend_parse_parameters_ex(ZEND_PARSE_PARAMS_QUIET, ZEND_NUM_ARGS(), 168 "s", &s, &length) == SUCCESS) { 169 /* manipulate string */ 170} else { 171 /* output error */ 172 173 return; 174} 175 176 177/* Function that accepts only varargs (0 or more) */ 178 179int i, num_varargs; 180zval *varargs = NULL; 181 182 183if (zend_parse_parameters(ZEND_NUM_ARGS(), "*", &varargs, &num_varargs) == FAILURE) { 184 return; 185} 186 187for (i = 0; i < num_varargs; i++) { 188 /* do something with varargs[i] */ 189} 190 191if (varargs) { 192 efree(varargs); 193} 194 195 196/* Function that accepts a string, followed by varargs (1 or more) */ 197 198char *str; 199size_t str_len; 200int i, num_varargs; 201zval *varargs = NULL; 202 203if (zend_parse_parameters(ZEND_NUM_ARGS(), "s+", &str, &str_len, &varargs, &num_varargs) == FAILURE) { 204 return; 205} 206 207for (i = 0; i < num_varargs; i++) { 208 /* do something with varargs[i] */ 209} 210 211/* Function that takes an array, followed by varargs, and ending with a long */ 212zend_long num; 213zval *array; 214int i, num_varargs; 215zval *varargs = NULL; 216 217if (zend_parse_parameters(ZEND_NUM_ARGS(), "a*l", &array, &varargs, &num_varargs, &num) == FAILURE) { 218 return; 219} 220 221for (i = 0; i < num_varargs; i++) { 222 /* do something with varargs[i] */ 223} 224
