1，创建一个新的扩展
./ext_skel --extname=return
2，修改config.m4，去掉没用的注释语句
cd return
vi config.m4
3，zend引擎在每个zif函数里定义了一个zval*类型的形参，名称为return_value，我们需要在函数里修改这个指针，函数执行完后内核将把这个指针指向的zval值返回
#define INTERNAL_FUNCTION_PARAMETERS int ht, zval *return_value, zval **return_value_ptr, zval *this_ptr, int return_value_used TSRMLS_DC
//ht
//zval *return_value 返回值
//zval **return_value_ptr
//zval *this_ptr，如果此函数是一个类的方法，那么这个指针的含义和PHP语言中$this变量差不多。
//int return_value_used，代表用户端在调用此函数时有没有使用到它的返回值。
4，用于返回值的宏
a) RETURN_BOOL(0); //返回bool值
//宏的定义(Zend/zend_API.h)
#define RETURN_BOOL(b) { RETVAL_BOOL(b); return; }
#define RETVAL_BOOL(b) ZVAL_BOOL(return_value, b)//操作return_value
#define ZVAL_BOOL(z, b) do { \
zval *__z = (z); \
Z_LVAL_P(__z) = ((b) != 0); \
Z_TYPE_P(__z) = IS_BOOL; \
} while (0)
//所以展开这个RETURN_BOOL(0)，最终在函数里返回值的操作即是：
do {
zval *__z = (return_value);
Z_LVAL_P(__z) = ((0) != 0); //定义return_value值
Z_TYPE_P(__z) = IS_BOOL; //定义return_value的类型
}while(0)
b) RETURN_STRING("hello world", 1); //返回字符串
//展开
do {
const char *__s = ("hello world");
zval *__z = return_value;
Z_STRLEN_P(__z) = strlen(__s);//定义长度
Z_STRVAL_P(__z) = (1?estrndup(__s, Z_STRLEN_P(__z)):(char*)__s);//定义值，estrndup函数实现字符串的复制
Z_TYPE_P(__z) = IS_STRING;
}while(0)
c)RETURN_LONG(100); //返回long值
//展开
zval *__z = return_value;
Z_LVAL_P(__z) = 100;
Z_TYPE_P(__z) = IS_LONG;
d)返回数组
array_init(return_value);//初始化return_value成数组，此操作完后就可以返回一个空的数组，$ret = array()
e)返回object
object_init(return_value);//初始化return_value成Object，此操作完成后返回一个空的对像
f)RETURN_RESOURCE(l);//返回resource
g)RETURN_NULL(); //return null;
h)RETURN_EMPTY_STRING(); //return "";
i)RETURN_ZVAL;
j)RETURN_FALSE; //return false;
k)RETURN_TRUE//return true;
#define RETVAL_RESOURCE(l) ZVAL_RESOURCE(return_value, l) //付值resource变量到系统返回值(return_value)
#define RETVAL_BOOL(b) ZVAL_BOOL(return_value, b) //付值bool变量到系统返回值(return_value)
#define RETVAL_NULL() ZVAL_NULL(return_value) //付值NULL到系统返回值(return_value)
#define RETVAL_LONG(l) ZVAL_LONG(return_value, l) //付值long变量到系统返回值(return_value)
#define RETVAL_DOUBLE(d) ZVAL_DOUBLE(return_value, d) //付值double变量到系统返回值(return_value)
#define RETVAL_STRING(s, duplicate) ZVAL_STRING(return_value, s, duplicate) //付值string变量到系统返回值(return_value)
#define RETVAL_STRINGL(s, l, duplicate) ZVAL_STRINGL(return_value, s, l, duplicate)
#define RETVAL_EMPTY_STRING() ZVAL_EMPTY_STRING(return_value) //返回empty string
#define RETVAL_ZVAL(zv, copy, dtor) ZVAL_ZVAL(return_value, zv, copy, dtor)//返回zval变量
#define RETVAL_FALSE ZVAL_BOOL(return_value, 0) //返回false
#define RETVAL_TRUE ZVAL_BOOL(return_value, 1) //返回true
#define RETURN_RESOURCE(l) { RETVAL_RESOURCE(l); return; }
#define RETURN_BOOL(b) { RETVAL_BOOL(b); return; }
#define RETURN_NULL() { RETVAL_NULL(); return;}
#define RETURN_LONG(l) { RETVAL_LONG(l); return; }
#define RETURN_DOUBLE(d) { RETVAL_DOUBLE(d); return; }
#define RETURN_STRING(s, duplicate) { RETVAL_STRING(s, duplicate); return; }
#define RETURN_STRINGL(s, l, duplicate) { RETVAL_STRINGL(s, l, duplicate); return; }
#define RETURN_EMPTY_STRING() { RETVAL_EMPTY_STRING(); return; }
#define RETURN_ZVAL(zv, copy, dtor) { RETVAL_ZVAL(zv, copy, dtor); return; }
#define RETURN_FALSE { RETVAL_FALSE; return; }
#define RETURN_TRUE { RETVAL_TRUE; return; }
5，数组函数
1)Zend's API for Associative Arrays
zval *arr;
MAKE_STD_ZVAL(arr);
array_init(arr); //$arr = array();
add_assoc_long(arr, "a", 10); //$arr["a"] = 10;
add_asoc_unset(arr, "a"); //unset(arr["a"]);
add_assoc_bool(arr, "b", 1); //$arr["b"] = true;
add_assoc_resource(arr, "c", 10); //$arr["c"] = $resource;
add_assoc_double(arr, "d", 2.15); //$arr["d"] = 2.15;
add_assoc_string(arr, "e", "hello", 1); //$arr["e"] = "hello";最后一个参数表示字符串值是否复制
add_assoc_stringl();
zval *sub;
MAKE_STD_ZVAL(sub);
array_init(sub);
add_assoc_zval(arr, "f", sub); //$arr["f"] = $sub;
2)Zend's API for Indexed Arrays, Part 1
zval *arr;
MAKE_STD_ZVAL(arr);
array_init(arr); //$arr = array();
add_index_long(arr, 1, 10); //$arr[1] = 10;
add_index_unset(arr, 1); //unset($arr[1]);
add_index_bool(arr, 2, 1); //$arr[2] = true;
add_index_resource(arr, 3, 10); //$arr[3] = $resource;
add_index_double(arr, 4, 2.15); //$arr[4] = 2.15;
add_index_string(arr, 5, "hello", 1); //$arr[5] = "hello";最后一个参数表示字符串值是否复制
add_index_stringl();
zval *sub;
MAKE_STD_ZVAL(sub);
array_init(sub);
add_index_zval(arr, 6, sub); //$arr[6] = $sub;
3)Zend's API for Indexed Arrays, Part 2
zval *arr;
MAKE_STD_ZVAL(arr);
array_init(arr); //$arr = array();
add_next_index_long(arr, 10); //$arr[] = 10;
add_next_index_unset(arr); //unset($arr[]);
add_next_index_bool(arr, 1); //$arr[] = true;
add_next_index_resource(arr, 10); //$arr[] = $resource;
add_next_index_double(arr, 2.15); //$arr[] = 2.15;
add_next_index_string(arr, "hello", 1); //$arr[] = "hello";最后一个参数表示字符串值是否复制
add_next_index_stringl();
zval *sub;
MAKE_STD_ZVAL(sub);
array_init(sub);
add_next_index_zval(arr, sub); //$arr[] = $sub;
6，Object函数
zval *obj;
MAKE_STD_ZVAL(obj);
object_init(obj);//$obj = new stdClass;
add_property_long(obj, "a", 10); //$obj->a = 10;
add_property_unset(obj, "a"); //unset($obj->a);
add_property_bool(obj, "b", 1); //$obj->b = true;
add_property_resource(obj, "c", 10); //$obj->c = $resource;
add_property_double(obj, "d", 2.15); //$obj->d = 2.15;
add_property_string(obj, "e", "hello", 1);//$obj->e = "hello"; 最后一个参数表示字符串值是否复制
add_property_stringl();
zval *sub;
MAKE_STD_ZVAL(sub);
object_init(sub); //$sub = new stdClass;
add_property_zval(obj, "f", sub); //$obj->f = $sub;
7，Zval
struct _zend_object_handlers {
/* general object functions */
zend_object_add_ref_t add_ref;
zend_object_del_ref_t del_ref;
zend_object_clone_obj_t clone_obj;
/* individual object functions */
zend_object_read_property_t read_property;
zend_object_write_property_t write_property;
zend_object_read_dimension_t read_dimension;
zend_object_write_dimension_t write_dimension;
zend_object_get_property_ptr_ptr_t get_property_ptr_ptr;
zend_object_get_t get;
zend_object_set_t set;
zend_object_has_property_t has_property;
zend_object_unset_property_t unset_property;
zend_object_has_dimension_t has_dimension;
zend_object_unset_dimension_t unset_dimension;
zend_object_get_properties_t get_properties;
zend_object_get_method_t get_method;
zend_object_call_method_t call_method;
zend_object_get_constructor_t get_constructor;
zend_object_get_class_entry_t get_class_entry;
zend_object_get_class_name_t get_class_name;
zend_object_compare_t compare_objects;
zend_object_cast_t cast_object;
zend_object_count_elements_t count_elements;
zend_object_get_debug_info_t get_debug_info;
zend_object_get_closure_t get_closure;
zend_object_get_gc_t get_gc;
};
typedef struct _zend_object_value {
zend_object_handle handle;
const zend_object_handlers *handlers;
} zend_object_value;
typedef union _zvalue_value {
long lval; /* long value */
double dval; /* double value */
struct {
char *val;
int len;
} str; /* string value */
HashTable *ht; /* hash table value */
zend_object_value obj; /* object value */
} zvalue_value;
struct _zval_struct {
/* Variable information */
zvalue_value value; /* 值 */
zend_uint refcount__gc; /* 引用计数 */
zend_uchar type; /* 变量类型 */
zend_uchar is_ref__gc; /* 是否引用变量， &$a */
};
#define ZVAL_FALSE(z) ZVAL_BOOL(z, 0) //设置zval
#define ZVAL_TRUE(z) ZVAL_BOOL(z, 1)
/* struct操作宏 */
#define Z_LVAL(zval) (zval).value.lval //获取long值
#define Z_BVAL(zval) ((zend_bool)(zval).value.lval) //获取bool值
#define Z_DVAL(zval) (zval).value.dval //获取double值
#define Z_STRVAL(zval) (zval).value.str.val //获取string的指针
#define Z_STRLEN(zval) (zval).value.str.len //获取string的长度
#define Z_ARRVAL(zval) (zval).value.ht //获取hashtable值
#define Z_OBJVAL(zval) (zval).value.obj //获取object值
#define Z_OBJ_HANDLE(zval) Z_OBJVAL(zval).handle //
#define Z_OBJ_HT(zval) Z_OBJVAL(zval).handlers //
#define Z_OBJCE(zval) zend_get_class_entry(&(zval) TSRMLS_CC) //
#define Z_OBJPROP(zval) Z_OBJ_HT((zval))->get_properties(&(zval) TSRMLS_CC) //
#define Z_OBJ_HANDLER(zval, hf) Z_OBJ_HT((zval))->hf //
#define Z_RESVAL(zval) (zval).value.lval //获取long值
#define Z_OBJDEBUG(zval,is_tmp) (Z_OBJ_HANDLER((zval),get_debug_info)?Z_OBJ_HANDLER((zval),get_debug_info)(&(zval),&is_tmp TSRMLS_CC):(is_tmp=0,Z_OBJ_HANDLER((zval),get_properties)?Z_OBJPROP(zval):NULL)) //
/* 指针操作宏 */
#define Z_LVAL_P(zval_p) Z_LVAL(*zval_p)
#define Z_BVAL_P(zval_p) Z_BVAL(*zval_p)
#define Z_DVAL_P(zval_p) Z_DVAL(*zval_p)
#define Z_STRVAL_P(zval_p) Z_STRVAL(*zval_p)
#define Z_STRLEN_P(zval_p) Z_STRLEN(*zval_p)
#define Z_ARRVAL_P(zval_p) Z_ARRVAL(*zval_p)
#define Z_OBJPROP_P(zval_p) Z_OBJPROP(*zval_p)
#define Z_OBJCE_P(zval_p) Z_OBJCE(*zval_p)
#define Z_RESVAL_P(zval_p) Z_RESVAL(*zval_p)
#define Z_OBJVAL_P(zval_p) Z_OBJVAL(*zval_p)
#define Z_OBJ_HANDLE_P(zval_p) Z_OBJ_HANDLE(*zval_p)
#define Z_OBJ_HT_P(zval_p) Z_OBJ_HT(*zval_p)
#define Z_OBJ_HANDLER_P(zval_p, h) Z_OBJ_HANDLER(*zval_p, h) #define Z_OBJDEBUG_P(zval_p,is_tmp) Z_OBJDEBUG(*zval_p,is_tmp)
/* */
#define Z_LVAL_PP(zval_pp) Z_LVAL(**zval_pp)
#define Z_BVAL_PP(zval_pp) Z_BVAL(**zval_pp)
#define Z_DVAL_PP(zval_pp) Z_DVAL(**zval_pp)
#define Z_STRVAL_PP(zval_pp) Z_STRVAL(**zval_pp)
#define Z_STRLEN_PP(zval_pp) Z_STRLEN(**zval_pp)
#define Z_ARRVAL_PP(zval_pp) Z_ARRVAL(**zval_pp)
#define Z_OBJPROP_PP(zval_pp) Z_OBJPROP(**zval_pp)
#define Z_OBJCE_PP(zval_pp) Z_OBJCE(**zval_pp)
#define Z_RESVAL_PP(zval_pp) Z_RESVAL(**zval_pp)
#define Z_OBJVAL_PP(zval_pp) Z_OBJVAL(**zval_pp)
#define Z_OBJ_HANDLE_PP(zval_p) Z_OBJ_HANDLE(**zval_p)
#define Z_OBJ_HT_PP(zval_p) Z_OBJ_HT(**zval_p)
#define Z_OBJ_HANDLER_PP(zval_p, h) Z_OBJ_HANDLER(**zval_p, h)
#define Z_OBJDEBUG_PP(zval_pp,is_tmp) Z_OBJDEBUG(**zval_pp,is_tmp)
/* 获取zval的变量类型 */
#define Z_TYPE(zval) (zval).type
#define Z_TYPE_P(zval_p) Z_TYPE(*zval_p)
#define Z_TYPE_PP(zval_pp) Z_TYPE(**zval_pp)
/* zval初始化宏 */
#define ALLOC_ZVAL(z) (z) = (zval *) emalloc(sizeof(zval)) //初始化zval，分配内存
#define FREE_ZVAL(z) efree_rel(z) //释放zvalue内存
#define ALLOC_ZVAL_REL(z)(z) = (zval *) emalloc_rel(sizeof(zval))
#define FREE_ZVAL_REL(z) efree_rel(z)
/* HashTable初始化宏 */
#define ALLOC_HASHTABLE(ht) (ht) = (HashTable *) emalloc(sizeof(HashTable)) //初始化HashTable
#define FREE_HASHTABLE(ht) efree(ht)
#define ALLOC_HASHTABLE_REL(ht) (ht) = (HashTable *) emalloc_rel(sizeof(HashTable))
#define FREE_HASHTABLE_REL(ht) efree_rel(ht)
#define INIT_PZVAL(z) (z)->refcount__gc = 1; (z)->is_ref__gc = 0; //设置refcount
#define INIT_ZVAL(z) z = zval_used_for_init;
#define ALLOC_INIT_ZVAL(zp) ALLOC_ZVAL(zp); INIT_ZVAL(*zp); //分配内存并设置默认值
#define MAKE_STD_ZVAL(zv) ALLOC_ZVAL(zv); INIT_PZVAL(zv); //分配内存并设置默认值
#define PZVAL_IS_REF(z) Z_ISREF_P(z)
/* 拷贝zval的值 */
#define ZVAL_COPY_VALUE(z, v) \
do { \
(z)->value = (v)->value; \
Z_TYPE_P(z) = Z_TYPE_P(v); \
} while (0)
#define INIT_PZVAL_COPY(z, v) \
do { \
ZVAL_COPY_VALUE(z, v); \
Z_SET_REFCOUNT_P(z, 1); \
Z_UNSET_ISREF_P(z); \
} while (0)
#define ZVAL_IS_NULL(z) (Z_TYPE_P(z)==IS_NULL) //判断zval是否为NULL
/* 设置zval为resource类型值 */
#define ZVAL_RESOURCE(z, l) do { \
zval *__z = (z); \
Z_LVAL_P(__z) = l; \
Z_TYPE_P(__z) = IS_RESOURCE;\
} while (0)
/* 设置zval为bool类型值 */
#define ZVAL_BOOL(z, b) do { \
zval *__z = (z); \
Z_LVAL_P(__z) = ((b) != 0); \
Z_TYPE_P(__z) = IS_BOOL; \
} while (0)
/* 设置zval为NULL */
#define ZVAL_NULL(z) { \
Z_TYPE_P(z) = IS_NULL; \
}
/* 设置zval为long值 */
#define ZVAL_LONG(z, l) { \
zval *__z = (z); \
Z_LVAL_P(__z) = l; \
Z_TYPE_P(__z) = IS_LONG; \
}
/* 设置zval为double值 */
#define ZVAL_DOUBLE(z, d) { \
zval *__z = (z); \
Z_DVAL_P(__z) = d; \
Z_TYPE_P(__z) = IS_DOUBLE; \
}
/* 设置zval为string值 */
#define ZVAL_STRING(z, s, duplicate) do { \
const char *__s=(s); \
zval *__z = (z); \
Z_STRLEN_P(__z) = strlen(__s); \
Z_STRVAL_P(__z) = (duplicate?estrndup(__s, Z_STRLEN_P(__z)):(char*)__s);\
Z_TYPE_P(__z) = IS_STRING; \
} while (0)
/* 设置zval为string值 */
#define ZVAL_STRINGL(z, s, l, duplicate) do { \
const char *__s=(s); int __l=l; \
zval *__z = (z); \
Z_STRLEN_P(__z) = __l; \
Z_STRVAL_P(__z) = (duplicate?estrndup(__s, __l):(char*)__s);\
Z_TYPE_P(__z) = IS_STRING; \
} while (0)
/* 设置zval为empty string值 */
#define ZVAL_EMPTY_STRING(z) do { \
zval *__z = (z); \
Z_STRLEN_P(__z) = 0; \
Z_STRVAL_P(__z) = STR_EMPTY_ALLOC();\
Z_TYPE_P(__z) = IS_STRING; \
} while (0)
/* 设置zval为zval值 */
#define ZVAL_ZVAL(z, zv, copy, dtor) { \
zend_uchar is_ref = Z_ISREF_P(z); \
zend_uint refcount = Z_REFCOUNT_P(z); \
ZVAL_COPY_VALUE(z, zv); \
if (copy) { \
zval_copy_ctor(z); \
} \
if (dtor) { \
if (!copy) { \
ZVAL_NULL(zv); \
} \
zval_ptr_dtor(&zv); \
} \
Z_SET_ISREF_TO_P(z, is_ref); \
Z_SET_REFCOUNT_P(z, refcount); \
}