ZEND_API void execute(zend_op_array *op_array TSRMLS_DC)
{
zend_execute_data *execute_data;
zend_bool nested = 0;
zend_bool original_in_execution = EG(in_execution);
if (EG(exception)) {
return;
}
EG(in_execution) = 1;
zend_vm_enter:
/* Initialize execute_data */
execute_data = (zend_execute_data *)zend_vm_stack_alloc(
ZEND_MM_ALIGNED_SIZE(sizeof(zend_execute_data)) +
ZEND_MM_ALIGNED_SIZE(sizeof(zval**) * op_array->last_var * (EG(active_symbol_table) ? 1 : 2)) +
ZEND_MM_ALIGNED_SIZE(sizeof(temp_variable)) * op_array->T TSRMLS_CC);
EX(CVs) = (zval***)((char*)execute_data + ZEND_MM_ALIGNED_SIZE(sizeof(zend_execute_data)));
memset(EX(CVs), 0, sizeof(zval**) * op_array->last_var);
EX(Ts) = (temp_variable *)(((char*)EX(CVs)) + ZEND_MM_ALIGNED_SIZE(sizeof(zval**) * op_array->last_var * (EG(active_symbol_table) ? 1 : 2)));
EX(fbc) = NULL;
EX(called_scope) = NULL;
EX(object) = NULL;
EX(old_error_reporting) = NULL;
EX(op_array) = op_array;
EX(symbol_table) = EG(active_symbol_table);
EX(prev_execute_data) = EG(current_execute_data);
EG(current_execute_data) = execute_data;
EX(nested) = nested;
nested = 1;
if (op_array->start_op) {
ZEND_VM_SET_OPCODE(op_array->start_op);
} else {
ZEND_VM_SET_OPCODE(op_array->opcodes);
}
if (op_array->this_var != -1 && EG(This)) {
Z_ADDREF_P(EG(This)); /* For $this pointer */
if (!EG(active_symbol_table)) {
EX(CVs)[op_array->this_var] = (zval**)EX(CVs) + (op_array->last_var + op_array->this_var);
*EX(CVs)[op_array->this_var] = EG(This);
} else {
if (zend_hash_add(EG(active_symbol_table), "this", sizeof("this"), &EG(This), sizeof(zval *), (void**)&EX(CVs)[op_array->this_var])==FAILURE) {
Z_DELREF_P(EG(This));
}
}
}
EG(opline_ptr) = &EX(opline);
EX(function_state).function = (zend_function *) op_array;
EX(function_state).arguments = NULL;
while (1) {
int ret;
#ifdef ZEND_WIN32
if (EG(timed_out)) {
zend_timeout(0);
}
#endif
if ((ret = EX(opline)->handler(execute_data TSRMLS_CC)) > 0) {
switch (ret) {
case 1:
EG(in_execution) = original_in_execution;
return;
case 2:
op_array = EG(active_op_array);
goto zend_vm_enter;
case 3:
execute_data = EG(current_execute_data);
default:
break;
}
}
}
zend_error_noreturn(E_ERROR, "Arrived at end of main loop which shouldn‘t happen");
}
struct _zend_op_array {
/* Common elements */
zend_uchar type;
char *function_name;
zend_class_entry *scope;
zend_uint fn_flags;
union _zend_function *prototype;
zend_uint num_args;
zend_uint required_num_args;
zend_arg_info *arg_info;
zend_bool pass_rest_by_reference;
unsigned char return_reference;
/* END of common elements */
zend_bool done_pass_two;
zend_uint *refcount;
zend_op *opcodes;
zend_uint last, size;
zend_compiled_variable *vars;
int last_var, size_var;
zend_uint T;
zend_brk_cont_element *brk_cont_array;
int last_brk_cont;
int current_brk_cont;
zend_try_catch_element *try_catch_array;
int last_try_catch;
/* static variables support */
HashTable *static_variables;
zend_op *start_op;
int backpatch_count;
zend_uint this_var;
char *filename;
zend_uint line_start;
zend_uint line_end;
char *doc_comment;
zend_uint doc_comment_len;
zend_uint early_binding; /* the linked list of delayed declarations */
void *reserved[ZEND_MAX_RESERVED_RESOURCES];
};
typedef struct _zend_op_array zend_op_array;
#define ZEND_INTERNAL_FUNCTION 1 #define ZEND_USER_FUNCTION 2 #define ZEND_OVERLOADED_FUNCTION 3 #define ZEND_EVAL_CODE 4 #define ZEND_OVERLOADED_FUNCTION_TEMPORARY 5
EX(opline)->handler(execute_data TSRMLS_CC))
#define ZEND_VM_NEXT_OPCODE() /
CHECK_SYMBOL_TABLES() /
EX(opline)++; /
ZEND_VM_CONTINUE()
#define ZEND_VM_SET_OPCODE(new_op) /
CHECK_SYMBOL_TABLES() /
EX(opline) = new_op
#define ZEND_VM_JMP(new_op) /
CHECK_SYMBOL_TABLES() /
if (EXPECTED(!EG(exception))) { /
EX(opline) = new_op; /
} /
ZEND_VM_CONTINUE()
#define ZEND_VM_INC_OPCODE() /
EX(opline)++
#define ZEND_VM_CONTINUE() return 0 #define ZEND_VM_RETURN() return 1 #define ZEND_VM_ENTER() return 2 #define ZEND_VM_LEAVE() return 3 #define ZEND_VM_DISPATCH(opcode, opline) return zend_vm_get_opcode_handler(opcode, opline)(ZEND_OPCODE_HANDLER_ARGS_PASSTHRU);
/* Executor */ #ifdef ZTS # define EG(v) TSRMG(executor_globals_id, zend_executor_globals *, v) #else # define EG(v) (executor_globals.v) extern ZEND_API zend_executor_globals executor_globals; #endif
struct _zend_execute_data {
struct _zend_op *opline;
zend_function_state function_state;
zend_function *fbc; /* Function Being Called */
zend_class_entry *called_scope;
zend_op_array *op_array;
zval *object;
union _temp_variable *Ts;
zval ***CVs;
HashTable *symbol_table;
struct _zend_execute_data *prev_execute_data;
zval *old_error_reporting;
zend_bool nested;
zval **original_return_value;
zend_class_entry *current_scope;
zend_class_entry *current_called_scope;
zval *current_this;
zval *current_object;
struct _zend_op *call_opline;
};
<?php
$a = 123;
test();
function test()
{
return 1;
}
?>
EX(op_array) = op_array; // 设置op_array字段为当前执行的op_array,也就是全局代码的op_array1 EX(prev_execute_data) = EG(current_execute_data);//将全局执行数据中保存的当前op_array执行数据保存到op_array1的execute_data1的prev_execute_data字段，由于这是执行的第一个op_array,所以prev_execute_data实际上是空值,然后将执行期全局变量的current_execute_data设置成execute_data1,然后设置execute_data1的当前执行op，这样就可以开始执行当前的op了
EG(active_op_array) = &EX(function_state).function->op_array;
case 2:
op_array = EG(active_op_array);
goto zend_vm_enter;
原文地址：http://blog.csdn.net/hello_katty/article/details/46557441
